Netbooting GS/OS allows you to load more functionality without an expensive hard drive controller. Since I've heard that the speed is comparable to a floppy diskette, you also remove the need to juggle floppies.

I'm not sure how netbooting would even work on a IIe, but I could imagine it being useful in schools. I remember the process of signing out a folder with the floppies while doing stuff in a Jr. High computer course. In retrospect, that was probably done to avoid having stuff walk off. (Even if there is no ill intent, teens forget.)