Ubuntu's decision to put the menus at the top of the screen was a usability disaster. I could see how it might make sense on a very small screen where vertical space matters. But for most desktop users, it just makes it a pain in the arse to use menus.
Likewise the decision to hide scrollbars. Hiding them may make sense on small screens, but if you have the space, it just increases the effort to scroll things.
It was smart to finally dump Unity for GNOME shell. I'm not sure about the decision to go back from Wayland - perhaps for a LTS release it makes sense but they should be doing their best to take X out of the baseline and defaulting back to Wayland would hasten that transition.