Yeah, my old desktop computer is getting turned into my first dedicated Linux machine and my current desktop isn't getting updated to 11 until October 13th.
Pretty much everything (except for games with kernal level anti-cheat as others have said) works now.
Even if Steam says "unsupported," there's a decent chance it will work out of the box, or maybe with a little tweaking. Protondb.com is a great resource for this.