In my experience, doesn’t matter. You can use lutris/bottles or install on a windows pc and copy files to the Deck and it’ll work, the distro is irrelevant in this case.

I stick with Steam OS because I don’t see any real world benefits of changing to another distro

Any distro will work. I have tried bazzite, cachyos, endeavouros and had same experience with gaming. In all the distros lutris was common.