1. Attrocious linux support. I use linux at work and its just a pure shitshow. Teams is only offered as PWA with horrible performance. Its far snappier on windows. There is even a community version called teams-for-linux which at least shows notifications in the tray icon and dock icon on ubuntu unlike the official one.
2. Groups are trash. You just wanna call 3 people? Well we made a group for you. Everytime you call a bunch of people it creates a group and that group is now a contact in your chat window. By now I have a group for every constillation of the team I work in. Its beyond annoying.
3. The text input tries to be too smart. Wanna insert code? You get a popup with your cursor in the „title“ part so if you press the code button and paste it ends up in the title. Great, gotta click in the textbox first.
4. Video calls arent much better. You sit next to a colleague and just wanna mute him cause you can hear him outside of teams? Yeah nope, not possible. Same goes for the missing feature of changing the volume of individual participants.
Discord does all of the things and is free for users. How in gods name is multi billion M$ not able to create a decent communication platform.