Recently we had a Teams outage at work that wasn't AWFULLY disruptive, but the only reason that is is that we don't depend on 365 cloud services to get anything done. We use Slack for chat features and more casual calling services (non-meeting) though of course Teams managed to be down on a meeting-heavy day, and we ended up organizing Slack huddles to get around it.

The only real cloud service we use is OneDrive and the CEO is pushing us to get away from it because it has all kinds of strange problems with file permissions and we constantly have to call IT to unlock files.