Maybe if those "modern" video-conference apps had one, decades old option that was (and still is) avaliable in
almost all gaming-oriented voice software (ventrilo, mumble, teamspeak, discord) called
PUSH 2 TALK
then this problem would be solved, same with the problem of kids/other people in the background (especially this)
but yea, we need AI/Blockchain based solutions that require thousands of hours of engineering effort that probably will be provided by some Startup and cost 15$.
It's insane how enterprise software is behind gaming in that particular matter, do those people even use their software?
</rant>
edit.
What's PUSH 2 TALK?
PUSH 2 TALK is not TURN ON / TURN OFF switch where you actually mute yourself. It's that you talk while having some button being pushed down e.g MOUSE SCROLL (MOUSE3) (for me it's probably one of the most practical choices)
so in this case you're always muted unless you want to talk
Why it's so great? because you can e.g play game, write code, do stuff on your PC and when you want to mute yourself, then you don't have to try to find some shortcuts or even worse - put video-co app on focus and click mute button, but instead you just stop pressing your PUSH2TALK hotkey! :P