At high frequencies the response of lower uF caps is faster than the response of higher uF caps. That's the way the math works out.
So to smooth the power to the devices, one uses a mixture of high and low capacitances. The low capacitance caps will respond quickly to small fluctuations, providing a small burst of compensating current, or absorbing a short burst of over-current. The higher capacity caps will have time to respond if the fluctuation lasts longer (lower frequency) and provide or absorb larger amounts of current to compensate.
Changing to a higher capacitance means that the capacitor will respond to fluctuations much more slowly. If there are enough other low capacitance capacitors in the circuit, it might not matter, but it's likely to leave a hole in the frequency smoothing.