We’re currently working on defining a compact mode experience. I will post more details when we have more to share.
Teams UI is an abomination. It's like communicating with sticky notes on a whiteboard. Allow a user to change their interface to allow for accessibility when required, but don't force everyone to read messages as if they were billboards.
This request is still being considered by the feature team but a final decision has not yet been made. I’m still awaiting more details.
Allow users to have a non-threaded view. Take it to e-mail if you want threads. UI devs need to eat the dog food in real companies, it seems.