For me "it just works" doesn't ring true. Generally at least once a day, I join a call and it won't let me unmute, and I have to restart Teams.

Scrolling through history is obnoxiously slow.

The activity feed is mostly useless, spammed with stuff that isn't important and it's the only place that vaguely tries to keep track of 'Teams' conversations.

In my company, I've been added to about 70 Teams and it's pretty much impossible to interact with them, so as a result no one does, they all just start ad-hoc chats, since that's the only thing that vaguely gets managed in a way people can follow.

When going cross-organization, it's a crap shoot whether or not we can use text, voice, and screen share/remote control. I know this is generally due to obnoxious company 'security' policies and other solutions have it, but it is a frustration. One recent call with a particularly screwed up company had us on two different meeting platforms at once as well as on an old fashioned conference call, because text was only allowed on one platform, screen share on another, and no audio was allowed on either (despite both supporting all three).

Sure, Teams suffers, in part, because like all corporate tools it connects you to generally dysfunctional work communities. However it broadly does have it's own annoyances.