I’m honestly thankful for this bit of lying. Windows 8 and below had horrible, horrible issues with fullscreen programs, especially games - they’d change your screen resolution and thus move and resize all your other windows, they’d freeze for ten seconds when you tried to alt-tab out, and they’d frequently just crash when you switched back to them. Those problems are essentially nonexistent nowadays, and it’s worth the small performance cost that comes from going through the compositor.