Maybe they fixed something because I'm currently in a training session with about 25 people with a bunch of breakout rooms and shared docs and CPU is hovering around the 3% mark (but we mandated that you only turn your video/mic on when speaking) and it's pretty snappy.

Still a bit confusing trying to find things but to be fair I have the same issue with most of these platforms.

I think this area will see an increasing amount of innovation and it's anybody's guess as to who will come out on top in the end.