Can't speak for Windows, but GNOME and KDE heavily use the window key by default for DE and window management functions. Applications are pretty free to use con

Can't speak for Windows, but GNOME and KDE heavily use the window key by default for DE and window management functions. Applications are pretty free to use control and alt keys to their heart's desire (they're free to use the window key too, but if the DE/WM captures a particular hot key, it won't work... it's not often that applications try to actually use it).