The HD video quality is surprisingly solid -- comparable to Zoom, far surpasses Webex and Google Hangouts -- and uses a different protocol, codec(s) and network than Skype for Business, which I have always found spotty. MS Teams is the slated successor to Skype for Business (good riddance).
https://www.djeek.com/2018/01/microsoft-teams-and-the-protoc...
It can handle up to 250 participants for group video chat (similar to Zoom), and there's an MS Teams Live Events edition that can handle 10k participants. (20k during COVID)
https://docs.microsoft.com/en-us/microsoftteams/teams-live-e...
It actually does a few things better than Zoom -- its virtual background feature is able to better detect and eliminate complex backgrounds. It recently introduced on-the-fly automatic closed captioning (through speech recognition). Later this year, it will have a larger video grid (currently the limit is 3x3) and AI-based noise cancellation on mic input -- previously the domain of offerings like krisp.ai.
On iOS devices, it even lets you do live screen-sharing on mobile (using Apple's Screen Recorder mechanism), which makes it easy to demo mobile apps on a video call.
EDIT: --I don't think Zoom let you do this (yet?)-- not a true statement, but leaving this here with strikethrough.