At this point in my life I'm just not willing to look at a desktop environment besides macOS and Windows unless it is completely different. Is there anything out there that is trying radical new concepts and not just trying to emulate macOS/Windows/Gnome/KDE et al?
I noticed in one of your comments in this thread that you are looking for new ideas for UI. As other commenters have said, you might be interested in tiling window managers like i3 [0] or sway [1]. They really are a gem for productivity and sometimes for the eye [2].
However, I love the concept of a scrollable window manager like PaperWM [3]. When I had a smaller screen (24" 16:9) I complained a lot about the unused space on my screen. With PaperWM I was finally happy with its dimensions, because I could have a huge IDE on the left and a small part of terminal on the right. This way I could see if something was being printed to the terminal, while my editor took up 80% of the screen.
[0]: https://i3wm.org/
[1]: https://swaywm.org/