Microsoft Teams is impressive that it actually manages to have a worse desktop client than Skype for Business, and the web site is barely any better. If people on O365 haven't used it, they should since Microsoft will force it on you sooner or later.
It is like Microsoft wanted to clone a bunch of popular services (e.g. Slack) and just mashed them all together without a care in the world, and to top it off had to make a bad UWP desktop application that needed touch support so they cut 90% of common features to fit in enough voidspace into the UI for touch.
[0] https://docs.microsoft.com/en-us/microsoftteams/faq-journey