I've been looking more and more at this since I got a Steam Deck and found surprisingly good compatibility on almost every game. If Steam OS was made available for your run-of-the-mill gaming rig I'd install it in a heartbeat and give it an earnest test run.
That said, there is still a latent unease from my last misadventure with a Linux gaming PC from 2017, which ended in a LOT of restarting into Windows whenever the guys wanted to play a game I couldn't get working
My only speedbump at this point is non-steam games, specifically in my case overwatch2 and diablo4. Can I run the battlenet launcher and it's games on steam os .. can i do it and not be banned by their 'anti cheat' spyware?
I saw that page right after I made the comment and googled it, but it seemed a little light on details and I was suspicious that it was the old Steam Machines distro as opposed to the frankly quite pleasant distro on the Steam Deck.
EDIT: Yep [1], it looks like that page is for the old SteamOS
Try Bottles (use bottles.com).. I smashed through the Diablo 4 Beta on VanillaOS and Bottles and can also confirm that Overwatch, Hearthstone, StarCraft and Diablo 3 works. The scaling / DPI for the BattleNet client is a little small on my 4K monitor, but other than that, it works well.
That said, there is still a latent unease from my last misadventure with a Linux gaming PC from 2017, which ended in a LOT of restarting into Windows whenever the guys wanted to play a game I couldn't get working