I imagine the people saying “it just works” are saying it because it does, at least for them.

SteamOS is based on Arch, but customized and aimed at specific hardware configurations. It’d be interesting to know what hardware you’re using and if any of your components are not well supported.

FWIW, I’ve used Steam on Linux (mostly PopOS until this year, then Bazzite) for years and years without many problems. ISTR having to do something to make Quake III work a few years ago, but it ran fine after and I’ve recently reinstalled it and didn’t have to fuss with anything.

Granted, I don’t run a huge variety of games, but I’ve finished several or played for many hours without crashes, etc.