Why are there only auto saves for MULTITRACK sessions and not just every session?

Since Multitrack and Waveform view work in completely different ways, then the answer is - a lot more difficult. And audio isn't backed up anyway, it's only session files that are. And relying on any form of cloud storage for original material - well, that's just asking for trouble.

Waveform view doesn't run 'sessions' as such - it works on files, and it does this destructively. The undos it stores are in temp files, which are inherently vulnerable; if your machine crashes, then you stand an incredibly good chance of losing them. Which means you have to be careful about what you do and don't do. Rule 1 for any sort of editing (even including what you do with Multitrack) is that you do not use your original files, especially if they can't be replaced; you always edit a copy, because then you have something to go back to.

What would you like it to save in waveform? Do you want it to automatically overwrite your audio file? In multitrack it saves the session file, doesn't change the audio at all.