I'm surprised to see just about all comments here agreeing with you. I was sure there would be a whole bunch of people saying that Teams is fine for their use, but I guess I'm in a minority as I actually don't mind using Teams and performance is fine. For reference, I just exited Teams and re-opened it and it took 13 seconds to open, log me in, and update my status. I do have an i7 CPU and 16GB RAM, but I wouldn't describe my laptop as performant - it's just a small and light ultrabook.