I bet the experience outside of Steam Deck depends a lot on the dist, graphics drivers and card and someone’s personal knowledge/willingness to screw around making everything work

In my experience, it’s been about the same. Then again, I also use an Arch based distro on my desktop, but I dunno, even when I distrohopped a lot and used other distros and hadn’t replaced some of my specs, gaming wasn’t a pain to setup or do in general unless it was something that specifically didn’t work with Linux (maybe modding was hard at first, but once I found out what worked for me, I was golden).