Google Meet is rolling out an Audio and Video Lock feature. With the latest feature, the Google Meet host can lock the microphones or cameras of all participants in a meeting, so no one can turn on their audio or video until the host unlocks them.

source https://gadgets.ndtv.com/apps/news/google-meet-audio-video-lock-feature-update-rollout-host-control-2583930#rss-gadgets-all