You are trying to replace in-person meetings without using cameras? It scales pretty well to a reasonable amount of people. How many people do you need in a meeting? If you have meetings with more than 12 people, then you are probably holding a conference and your meetings suck anyway. A written announcement would work better.
You are trying to bend reality to your will, it doesn't work like that. The fact of the matter is that sometimes you have large meetings, and often times participants will have their cameras turned off. Instead of fighting it and saying that people are Doing It Wrong, we need to accept this reality and work with it.
A push-to-talk system with shared layouts solves all these problems, is scalable, and doesn't require cameras.
Can't fit arbitrarily large numbers of people on a laptop screen, it's way harder to pick up this kind of motion from a mosaic of small 2d tiles, and everyone needs their camera on which isn't always feasible (connection issues, privacy of others in a home office setting, etc.)
Did your in-person meetings ever had this many participants? If this many people needs to be involved, then I'll argue a meeting is a nonsense anyway. It would be extremely hard even in-person.