[progman32]

In all my meeting software (the usual suspects running in the browser) the mic is always opened at the driver level, even if I'm muted. Perhaps it's to avoid latency when you unmute, or perhaps it's for those "you're muted" pop-ups.

[freedomben]

Yes, this and also potential permission issues. If the first time you try to talk you get prompted for microphone permissions, it can be highly disruptive