For gaming, I don’t really understand why anyone would prefer slower update cycles since there are frequent updates that fix compatibility or increase performance.

Which game uses host system libraries? I think you have a wrong impression how things work in Linux gaming outside of Tux Kart these days. Valve maintains their own set of Linux containers called Steam Linux Runtimes and their entire point is to be relatively slow moving. Just have a look at all the package dates at https://repo.steampowered.com/steamrt4/images/latest-public-stable/sources/

On top of that, almost every game is a proprietary Windows application. So it runs on top of Proton which sits on top of the latest Steam Linux Runtime.

It's similar with FOSS games where the foremost distribution outlet is Flathub and software published there relies on Flatpak Runtimes which are also relatively slow moving.

CachyOS is apparently “optimized” for gaming performance—I don’t pretend to know what that means or how much of an impact it has.

Barely any unless you're installing FOSS games from their own repository for the reasons I outlined initially.

I’m super impressed with how well everything just works

And that's what's important.