It's improved greatly with Steam's work on Proton, at a guess I'd say at least 75% of my library is now playable with no extra work from my side.
On Windows it's still 100% though.
With a goal of 1440p@144hz, and someone who appreciates visual fidelity, I own an RTX 2080 Ti, and there's just far too much of a performance penalty for linux gaming.
Why did you buy that if you planned to game on Linux? I got a Vega 56 and it works great. Right now I'd opt for one of the newly released cards. With a Ryzen 3... AMD is back!
In fact, WINE supports packages that Windows no longer can.