I've done a lot of video calls since pandemic started, usually with our company's chosen vendor, but with some outside companies, it's on their system. It was only a couple weeks ago that I experienced my first Teams call ever, while I've had many external zoom calls, many Google, some Chime, some webex, and I've had many, many external Slack invites.

I wonder if Microsoft's Teams numbers were pumped up by it being freely included in O365 subs. "Oh you're a paying O365 customer; we'll just go ahead and count your included Teams sub as a Teams sub."