> I've heard that with regards to video conferencing, it's competitive with zoom.

Did you hear that from a Microsoft salesperson? Only a person who hasn't used both regularly can say that. UX and features on Zoom are better.

The mere fact that to this day Teams has wildly different features depending on how you join the call is a joke - for instance, joining from a browser on macOS results in no chat (the button simply isn't there).

I've been in a "mixed" slack/teams environment and it seems there was always a push to be a little more teams-y every month or so - given that Github is owned by MSFT, I wouldn't be surprised if that happened there, too.

That makes a huge difference. It's worth editing the title to add "for video conferencing".

My current company had the same thing happen on acquisition, we had to ditch Zoom for Teams for video, but could stay on Slack. I find Teams video absolutely fine. It just works and I never think about it.