Have each app retain the same style and common functions.
The UI is a mess of different apps’ formats. They should all have identical “look and feel” – ie., the same positioning of the “close” icon, and volume control, etc. I am always having to search the whole display to find the icon that I want.
For example, why does YouTube have a tiny volume slider at the top of the screen? Other games and TeslaTheater apps could have a lot more consistency.