This is a bad answer. It's actually a non-answer. You can apply this to a lot of questions. Why does X ... Y (because X can get away with it).
There are real resources behind Microsoft Teams and a lot of people want it to be good. They may not get much of a signal about how well their product is doing compared to competitors because lock-in effects, but I can guarantee you the product managers and executives at Microsoft want the product to work well.
There are real resources behind Microsoft Teams and a lot of people want it to be good. They may not get much of a signal about how well their product is doing compared to competitors because lock-in effects, but I can guarantee you the product managers and executives at Microsoft want the product to work well.