Comment by Orygin

> Yes, there are many UI implementations in Windows but they are almost totally transparent to the user (no pun intended), and they can all run on the same system at once.

Just like Linux. You can run most if not all apps in any DE. Yes gnome will look ugly, but that's gnome's way of doing things. If you pick a decent DE, you will have most basic apps using the same styling, and the rest have CSD anyway.

Each GUI toolkit has its own specialties, but you'll use at most two of them, and they will be kept in separate apps. (Apart from flatpak portals which use gtk instead of the system's).

Windows has 3-5 different UI/UX layers within the same application ... And the rest have CSD anyway, so they look the same no matter the OS.