Earlier quoted context omitted.
Saw your comment too late and already made my own ( https://news.ycombinator.com/item?id=13641706 ). I'm wondering what your CPU usage looks like in Zoom sessions when just participating vs. when you're sharing your screen.
Sharing screen with Zoom takes a decent amount of CPU, compared to just talking, which eats only about 5-10% from my experience.
Which platform and hardware are you on?