The main thing is that Plasma 6 comes with some HDR support and it is possible to have it in some games now as well as in some apps like mpv that also have HDR support.

As for the Garuda Gamer version of the distro, it comes with a bunch of gaming stuff preinstalled and a Garuda Gamer app which makes it really easy to install gaming related apps, emulators, and hardware support for controllers, rgb, and all that kind of thing. It's just all handled very well and would make a nice distro to recommend to gamers who might want to make a switch to Linux from Windows, mainly because things are made so easy - which is nice for an Arch based distro because you have access to yay without it being overly complicated.