Until monopoly, or until 15-20% when companies start offering widespread Linux support for applications and peripheral management, and retail stores start selling some devices with a Linux desktop preloaded?

I'd do the math, but it really depends on whether the recent growth holds, accelerates, or slows down again. So, hard to tell.

I'm almost confident it'll slow down, or regress a little bit, historically that's what happens when it grows and then it'll equalize again around 2-3%.

The moment another or a few new AAA titles with kernel-level anti-cheat come out, people go back to Windows.

Gaming could, and probably will, be the key to the "Year of the Linux desktop" but the anti-cheat problem needs solved.