I regularly edit Team's messages that I notice a typo in, and there is no way that any important emails get sent out without being revised before clicking send -- that way major embarrassment lies.

You are aware that the Nazi's weren't communist aren't you?

Moving from a Slack company to a Mattermost one was horrible! Mattermost looks like someone wrote it in VB6 after a 10 minute conversation with someone else that watched someone using slack once!

And Teams isn't great, but at least its better than Mattermost and Skype for Business.