As a datapoint, I use Teams on Linux (desktop app) and I have to say that I love it. I would not say it is slow and clunky as you say.
I haven't had the inclination to investigate, but I suspect it's something like a memory leak that eats up all the (16GB) RAM and then swaps the system to death. Maybe if I was patient enough I could get an alternative console prompt and poke around, but when you need to get back into that meeting....