Teams is nice enough when it works, but it tend to break far more than any other chat app I used. Stuff like getting the call notification (won't work on Firefox, I have to launch Chrome even though I can join a meeting on Firefox). The most annoying is that sometime it just doesn't display anything. Like no notification on my phone, or the lastest message will sometime not appear on a device.

Teams also have some very nice things going for it with it's Office 365 integration, but as a chat app it's just way more buggy than it should.