I have a fancy microphone, but when I’m away from home in a low bandwidth situation I often phone in audio to zoom because it lags less. Lagging video and non-lagging audio seems to bother people less than both lagging.

Just because people say it's "taking up their bandwidth" doesn't mean that's what's actually happening.

It might be causing some other kind of issues but a microphone can't really "take up someone's bandwidth"... That's not really how things work.