Earlier quoted context omitted.
Which parts are a mess? I don't think I could use Linux if it weren't for Linux Mint/Cinnamon specifically, as I haven't had good experiences with other desktop enviroments. It has one or two quirks, but at this point it's far less quirks than a fresh Windows install and the list of config options I had to change/the .reg file I started accumulating
> Which parts are a mess? Usability conventions between GUI applications. Keyboardability. GUI automation à la AutoHotKey. Font rendering. X vs. Wayland.
On any Linux DE, you have native configurable key shortcuts (binding commands to keystrokes).
On KDE, Win+right-click for resizing a window from anywhere in the window (no need to click the edges) is awesome. Win+left-click for moving a window from anywhere in the window (no need to click the title bar) is awesome. Ctrl+Alt+Esc to turn your cursor into a little skull and crossbones and instantly kill whatever program you click the window of is awesome. Dolphin is amazing compared to Explorer (tabs, split views, rich file metadata displayed right below filenames).
Alt+tab to summon krunner, a tiny temporary window in the middle of the screen. Type the name of an app, Enter, and it launches. Type a math equation, and it evaluates it. Type "define" and a word, and it pulls a dictionary definition.
Clipboard history in the tray (works with pictures!). Related, Flameshot, which puts Window's Snippet Tool to shame. Like on Windows, Win+. for the emoji picker, but with more modern emojis than Windows currently supports. Customizable emoji fonts, too, unlike on Windows (Twemoji, the one Discord uses, is the best).
Gwenview is better than Window's Photos, and Okular is better than Adobe Reader.
Windows UX has nothing on KDE's UX, and I never wanna go back to an OS that can't translate billions of dollars to features I can get for free because it treats me as a dataminable cost center.