There are distributions with a great Steam experience out of the box? It’s SteamOS actually a good choice? Maybe isn’t what you use or prefer.
A good Steam distro for me has a very mininal procedure for perfectly working controllers, client and general user experience.
Your direct test and experience are very appreciated.
If you want minimal effort to get a good Linux setup for Steam, just buy a SteamDeck. Get the dock if you want to use it like a regular computer or console with a wireless gamepad. I did that – hooked it up to my monitor, headphones, plugged in a mouse, keyboard, and my old XBox360 USB wireless dongle and it all just worked. I’ve got a few ideas for fun projects I want to try with it as a handheld and have written some software on it using desktop mode (little Python utility scripts for shuffling data around) but mostly I just use it like a gaming console; it works well for that.