Like the old expression, You can never have too much money.... (guitars and guns would also be qualifiers) ...... this also holds true for interface inputs and outputs.

However, if you are a simple one man studio operator, and mostly just do songwriting demos and such things.... two inputs for audio can be over kill. Unless you have other folks over to jam and record in real time, two inputs is usually sufficient. However, if you need them , and have the funds available, and have the software that will support multiple inputs, by all means, indulge yourself and get the gear you want.

In my case, I have a 2 input focusrite and 98% of the time I use ONE input at a time. I really can't recall the last time I actually used both audio inputs at the same time. I do remember doing this a long time ago with one mic on the acoustic and another recording the vocal..... just to see how it all worked. Since then... nope... haven't done it again. Everything I do is one track at a time.

OUTPUTS... on the other hand, yeah, the more the better IMHO. My Saffire has 8 outputs and I have them all filled and I have an expander on one of them to give me 4 more outputs.

Since the outputs are assignable, you have to count 2 outputs as ONE L/R stereo pair so essentially, my 8 outputs is only 4 stereo outputs. Over time I have moved things around, but currently, one pair goes to the studio monitors, another pair to the stereo system for other playback options, the third pair to an external audio recorder, and the fourth pair into a 4 channel headphone amp, because one headphone out is never enough.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.