If you want to skip straight to the piracy, here's an open source package for you, complete with keys, hosted ironically on Microsoft servers, that uses vlmcsd: https://github.com/ekistece/vlmcsd-autokms
It's a pretty clever hack. It runs the KMS emulator locally and fakes the network connection with a TAP device from OpenVPN. Works perfectly.
I tried using wine or even using Steam directly on Linux, but playing any game with 30-40% less performance is ridiculous.
If you really like games, Linux is unusable for anything big.
I've had to dual boot Windows for the last 10 years just to play a game without stuttering, lag, huge FPS drops, etc.
Nothing would make me happier than being able to only use Linux, but until the community takes gaming seriously, people are forced to use Windows.
I'd argue if it was the issue, even Windows wouldn't let me play any of these games with reasonable performance.
When playing CS:GO (a relatively old game) I have stuttering, drastic FPS drops and more :(
It's a shame, because it literally can't be anything but the software. It's the same hardware with different OSes. Might even be windows specific optimizations on the games part, but in the end it doesn't matter.
The bottom line unfortunately is: it's significantly worse.
The complexity of setting this up would be a good point to address. Linux Mint for example has a tool to do this for you. This is logically a workaround for nvidia actually contributing an open source driver that doesn't suck.
There is a supposedly much better supported open source driver for new AMD hardware as well. Another thing the community is doing.
If the problem is with the closed source driver there isn't much the community can do. It's very hard to reverse engineer a complex device like a gpu. If the problem isn't games in general but that particular game there again isn't much the community can do.
Personally, I don't have that kind of problem, and I suspect I'm not alone. Of the games I play that don't have Linux ports, they run well enough under wine, even on my (recent) laptop with Intel graphics. But I'm a pretty casual gamer, and honestly find it rare that I just must play the type of games that require a high-end Windows rig.