I'd love to see evidence otherwise, but I do think that desktop interfaces are pretty "done" at this point - you can have a couple different paradigms and layouts, but usually it's the same thing - either a Windows 7-style taskbar/start menu layout, or a macOS dock/statusbar layout. There's not been much change in the desktop space in a long time. Features here, animations there, but desktops are relatively stagnant. The cool thing is that you can extend them with other programs if you want, but mostly they're just a way to launch programs. Not a lot of messing around is needed if you ask me.
I'd love to see evidence otherwise, but I do think that desktop interfaces are pretty "done" at this point - you can have a couple different paradigms and layouts, but usually it's the same thing - either a Windows 7-style taskbar/start menu layout, or a macOS dock/statusbar layout. There's not been much change in the desktop space in a long time. Features here, animations there, but desktops are relatively stagnant. The cool thing is that you can extend them with other programs if you want, but mostly they're just a way to launch programs. Not a lot of messing around is needed if you ask me.