I haven't used it myself, but I've heard lots of non-tech people say they like it. I think they are probably comparing it to skype/email rather than to slack.
I’d rather teams did 2 (albeit complex) things; Direct & Channel chats (with one or more people), and video calls with one or many people. If I want to use Office, I’ll use the right app.
It feels like Teams is trying to do too many things, and it’s bad at all of them.
I sync my files from Teams using OneDrive, and then they open in the desktop apps...and work like a regular folder in Windows