Turn off "Meeting Lobby Feature" at User Level
Ability for Each User to turn of "Lobby" feature for meetings forever. A simple checkbox binary option.
"Do you want your Teams Meetings to have a lobby from which you must admit members?" Yes/No
Then, you don't have to manually do it each meeting. But you could still turn it on for individual meetings, if you'd like.
In the meantime (Until MS takes care of the obvious flaw in the UX), if you view the participant list on the right sidebar, you'll avoid the ridiculous pop-ups in the middle of your content.
Dale Fitzgerald commented
Either silencing the notification or set participant permissions for who can admit participants in the lobby.
Kiar Pach commented
Would love to have the notification silenced for people in lobby!
It's very distracting during meetings. Would be great to be able to at least silence the notification.