I’ve got an oled display, does it have HDR? Gnome has a handful of extensions that I love, is Cosmic extensible?

Technically correct, famously the best kind of correct. Context be damned.

Mate, that technical detail is hardly useful to someone asking which distro might be good for gaming. The whole thing of distros is they are a collection of opinions around a Linux kernel. Are you really suggesting those differences are meaningless, especially to a beginner?

There are distros with highly customised kernels that are objectively better for gaming (higher and more consistent framerates).