Not counting the Steam Deck, since KDE isn’t actually turned on while you’re running games.
Normally I’m a Gnome guy, but I’m building a tiny low power portable computer and wanting to keep resource utilization low, so I’m investigating other options.
Gnome on my desktop and laptop. I use xfce when working in a vm, because it’s a bit lighter (I usually just need a terminal + text editor). I prefer gnome for regular use.