I notice the browser version is a little resource intensive. I use it on freebsd and I need to renice the browser to -10 for it to be somewhat stable. (This is an improvement because I remember 6 years ago it didn't work on freebsd.) I ran it on a Mac last week and it spun the fan more than I'd expect.
Last time I looked at their web client, it was indeed doing absurd things (I think it used TCP and web sockets to carry video instead of WebRTC and shipped a WASM video codec that obviously can’t be GPU/hardware accelerated).
Not sure if that’s malice (to nudge people towards using their invasive desktop app) or incompetence.