I'm going to respond here in two parts.
First I'll go after the OP and describe what I can accomplish on a classic Mac OS machine (more specifically a 68K running System 7) and what I can't. I am probably about as good a candidate as any for this exercise because I don't use streaming media services (Spotify, Pandora, etc.) or cloud storage services (Dropbox etc.). I run my own email accounts (both personal and work), which are completely standard-fare setups that should not pose a challenge for an old machine. Breaking things down further:
Text editing, email, and IRC all happen via ssh to my Unix shell server, which works almost as well on the classic Mac OS as it does on any modern non-Unix platform (see: PuTTY on Windows). This also conveniently lines up with how many people accessed networked services on the machines when they were new, just through telnet or rsh or some other precursor to SSH instead. The only problem connecting to modern machines here is character encodings - the PowerPC version of MacSSH supports legacy Japanese character encoding translation (ISO-2022-JP, EUC-JP and Shift-JIS), but the 68K version doesn't, so non-Roman system locales on the remote Unix machine are a problem. This means most application strings and content are illegible when I connect from a 68K machine, and are also illegible from a PowerPC machine unless I change the environment to a legacy encoding, although I can issue commands and do some other basic tasks. If we are willing to assume a PowerPC machine, then this issue becomes less severe, but it's still not very practical. I could switch my shell environment from UTF-8 to EUC-JP to allow MacSSH/PPC to display localized messages, but text files and emails I try to view in UTF-8 would still be illegible without conversion.
Music is a bit more complicated, and I probably wouldn't be happy with any classic Mac OS solution. My primary computers today are Unix machines running mpd clients on a FLAC collection, and even Mac OS X is not so great at this. I only know of one dedicated music player for OS X that does FLAC, which was written by a friend and is very much a proof of concept, although I would probably get by on it if I suddenly found myself with only OS X machines. I'm not aware of any classic Mac OS players that handle FLAC, and the disk space required to store the collection is is pushing the limits of hard disks that tend to be available for machines that run it, so I don't think I would ever attempt to use the platform for playing music in the present day.
Network resource access isn't bad - I run netatalk on my Solaris desktop at home and my 7.6.1 machines have no trouble with it. Not needing to use an FTP client or similar to move files between the old Macs and modern machines certainly goes a long way in this thought exercise.
The only thing I use a word processor for at all is my resume, which doesn't get updated often and actually does exist as a Nisus Writer document on my 840AV that I turn into a PDF when I need to send it somewhere. Any other significant text generation for me happens in an editor, which is usually vim and easily done over SSH, but I've been warming up to MPW lately as I hammer away at some hobby projects.
Web browsing is a very sore spot. Classilla and the old Mozilla releases it's based on are okay in a pinch, but Mac OS is really just not very good at handling the gigantic pile of scripts and content that comprise a modern website, and the rendering for many pages is way off. It's adequate for when I am doing something related to old computers and need to look up some online reference material, but I wouldn't suffer through my regular news sites on it, for example.
Where does this leave us? If the question is "would you use a classic Mac OS machine as a primary computer," the answer is an immediate "no," even if that computer were the fastest, most heavily-upgraded OS 9 machine possible. Browsing the web does not work very well unless you're very choosy about which sites you visit, I am not aware of any music player that would do what I need, and video playback is right out because the machines are not powerful enough to play HD video files regardless of OS or player, which is most of my collection by now. I could get a fair amount of work done in MacSSH on a PowerPC machine, but I would have to give up most if not all entertainment, doing research on the web would be a challenge, and I would have to convert many of my emails and other communication from UTF-8 to a legacy encoding before reading it, and then back to UTF-8 to reply. If you change the question to "would you use a classic Mac OS machine as a sidekick for a modern machine," the answer is yes. I like them and they're good at a subset of still-relevant tasks. For the past few weekends I've spent afternoons in my local coffee shop programming on a PowerBook 1400, and that was the only machine I had on me while there. When I get home, though, I might want to play some music or watch a movie, or read some news on a website, and that needs to happen on something newer and running a different OS.
Changing gears - some other issues were brought up regarding the nature of this community and the irresponsibility of having old OS X machines on the internet. The scope of the "old Mac" hobby varies from person to person, and I have seen some people make an unspoken assumption that any community focused on some kind of Apple product is inherently going to champion all other Apple products, or at least all other discontinued ones. For me personally, an "old Mac" hobby means machines that run the classic Mac OS, not OS X, and the appropriate scope of a place with a name like "68kMLA" is about that range - early PowerPC machines get a pass because they're running the same software platform. Old OS X machines to me are a different platform, and simply aren't different enough from a new Mac you can buy today to be interesting as an object of hobby interest. If someone else does think they're worthy of that interest, I'm in no position to criticize (although if someone is trying to get by on an old Mac because they can't or don't want to spend money on a new one, they've chosen the wrong platform). That being said, expecting a community officially centered around 68K Macs to embrace older OS X machines to me is about as absurd as expecting participants in an Apple II hobby community to be into 68K Macs. Some of them might be, but it's not part of the mission statement and one can't assume that they are. Ultimately 68kMLA is about a platform (classic Macintosh), not a brand (Apple). It's also not LowEndMac, whose mission statement has always been "we want to help you be a Mac user on the cheap by getting the most out of your old/used machine." People can talk about G4s and G5s running OS X all they want in the appropriate subforums, but don't ever expect the site admin or any regular user to be into those machines just because of their affiliation with 68kMLA. Some people are, but it's a degree removed from the stated focus of the community and it can't be expected.
The peculiar characteristics of the classic Mac OS that Cory5412 mentioned earlier - not being modern multiuser networked operating systems with a host of exploitable services - have actually helped bring me full circle with my obscure platform interest back to the 68K Macs that I started from. For a while I was more into SGI IRIX machines, but patch support for them ended in December 2013 and I prompty retired them all because it's simply not responsible to have unpatched Unix machines hanging out on the internet. 68K Macs don't have this problem, though, and I appreciate how I can get my old computer fix without having to quarantine them. It's the reason why I have no reservations about letting my Quadra 840AV see the internet, but I don't feel comfortable doing the same with my NeXTstation.
EDIT: Fixed factual error about MacSSH's Japanese character encoding support. I originally said that the PowerPC version can encode/decode Unicode, but actually the PowerPC version only supports legacy encodings, and the 68K version doesn't support any at all.
First I'll go after the OP and describe what I can accomplish on a classic Mac OS machine (more specifically a 68K running System 7) and what I can't. I am probably about as good a candidate as any for this exercise because I don't use streaming media services (Spotify, Pandora, etc.) or cloud storage services (Dropbox etc.). I run my own email accounts (both personal and work), which are completely standard-fare setups that should not pose a challenge for an old machine. Breaking things down further:
Text editing, email, and IRC all happen via ssh to my Unix shell server, which works almost as well on the classic Mac OS as it does on any modern non-Unix platform (see: PuTTY on Windows). This also conveniently lines up with how many people accessed networked services on the machines when they were new, just through telnet or rsh or some other precursor to SSH instead. The only problem connecting to modern machines here is character encodings - the PowerPC version of MacSSH supports legacy Japanese character encoding translation (ISO-2022-JP, EUC-JP and Shift-JIS), but the 68K version doesn't, so non-Roman system locales on the remote Unix machine are a problem. This means most application strings and content are illegible when I connect from a 68K machine, and are also illegible from a PowerPC machine unless I change the environment to a legacy encoding, although I can issue commands and do some other basic tasks. If we are willing to assume a PowerPC machine, then this issue becomes less severe, but it's still not very practical. I could switch my shell environment from UTF-8 to EUC-JP to allow MacSSH/PPC to display localized messages, but text files and emails I try to view in UTF-8 would still be illegible without conversion.
Music is a bit more complicated, and I probably wouldn't be happy with any classic Mac OS solution. My primary computers today are Unix machines running mpd clients on a FLAC collection, and even Mac OS X is not so great at this. I only know of one dedicated music player for OS X that does FLAC, which was written by a friend and is very much a proof of concept, although I would probably get by on it if I suddenly found myself with only OS X machines. I'm not aware of any classic Mac OS players that handle FLAC, and the disk space required to store the collection is is pushing the limits of hard disks that tend to be available for machines that run it, so I don't think I would ever attempt to use the platform for playing music in the present day.
Network resource access isn't bad - I run netatalk on my Solaris desktop at home and my 7.6.1 machines have no trouble with it. Not needing to use an FTP client or similar to move files between the old Macs and modern machines certainly goes a long way in this thought exercise.
The only thing I use a word processor for at all is my resume, which doesn't get updated often and actually does exist as a Nisus Writer document on my 840AV that I turn into a PDF when I need to send it somewhere. Any other significant text generation for me happens in an editor, which is usually vim and easily done over SSH, but I've been warming up to MPW lately as I hammer away at some hobby projects.
Web browsing is a very sore spot. Classilla and the old Mozilla releases it's based on are okay in a pinch, but Mac OS is really just not very good at handling the gigantic pile of scripts and content that comprise a modern website, and the rendering for many pages is way off. It's adequate for when I am doing something related to old computers and need to look up some online reference material, but I wouldn't suffer through my regular news sites on it, for example.
Where does this leave us? If the question is "would you use a classic Mac OS machine as a primary computer," the answer is an immediate "no," even if that computer were the fastest, most heavily-upgraded OS 9 machine possible. Browsing the web does not work very well unless you're very choosy about which sites you visit, I am not aware of any music player that would do what I need, and video playback is right out because the machines are not powerful enough to play HD video files regardless of OS or player, which is most of my collection by now. I could get a fair amount of work done in MacSSH on a PowerPC machine, but I would have to give up most if not all entertainment, doing research on the web would be a challenge, and I would have to convert many of my emails and other communication from UTF-8 to a legacy encoding before reading it, and then back to UTF-8 to reply. If you change the question to "would you use a classic Mac OS machine as a sidekick for a modern machine," the answer is yes. I like them and they're good at a subset of still-relevant tasks. For the past few weekends I've spent afternoons in my local coffee shop programming on a PowerBook 1400, and that was the only machine I had on me while there. When I get home, though, I might want to play some music or watch a movie, or read some news on a website, and that needs to happen on something newer and running a different OS.
Changing gears - some other issues were brought up regarding the nature of this community and the irresponsibility of having old OS X machines on the internet. The scope of the "old Mac" hobby varies from person to person, and I have seen some people make an unspoken assumption that any community focused on some kind of Apple product is inherently going to champion all other Apple products, or at least all other discontinued ones. For me personally, an "old Mac" hobby means machines that run the classic Mac OS, not OS X, and the appropriate scope of a place with a name like "68kMLA" is about that range - early PowerPC machines get a pass because they're running the same software platform. Old OS X machines to me are a different platform, and simply aren't different enough from a new Mac you can buy today to be interesting as an object of hobby interest. If someone else does think they're worthy of that interest, I'm in no position to criticize (although if someone is trying to get by on an old Mac because they can't or don't want to spend money on a new one, they've chosen the wrong platform). That being said, expecting a community officially centered around 68K Macs to embrace older OS X machines to me is about as absurd as expecting participants in an Apple II hobby community to be into 68K Macs. Some of them might be, but it's not part of the mission statement and one can't assume that they are. Ultimately 68kMLA is about a platform (classic Macintosh), not a brand (Apple). It's also not LowEndMac, whose mission statement has always been "we want to help you be a Mac user on the cheap by getting the most out of your old/used machine." People can talk about G4s and G5s running OS X all they want in the appropriate subforums, but don't ever expect the site admin or any regular user to be into those machines just because of their affiliation with 68kMLA. Some people are, but it's a degree removed from the stated focus of the community and it can't be expected.
The peculiar characteristics of the classic Mac OS that Cory5412 mentioned earlier - not being modern multiuser networked operating systems with a host of exploitable services - have actually helped bring me full circle with my obscure platform interest back to the 68K Macs that I started from. For a while I was more into SGI IRIX machines, but patch support for them ended in December 2013 and I prompty retired them all because it's simply not responsible to have unpatched Unix machines hanging out on the internet. 68K Macs don't have this problem, though, and I appreciate how I can get my old computer fix without having to quarantine them. It's the reason why I have no reservations about letting my Quadra 840AV see the internet, but I don't feel comfortable doing the same with my NeXTstation.
EDIT: Fixed factual error about MacSSH's Japanese character encoding support. I originally said that the PowerPC version can encode/decode Unicode, but actually the PowerPC version only supports legacy encodings, and the 68K version doesn't support any at all.