It peaked at 4.05% in March. The last 2 months it went just below 4% as the Unknown category increased. For June the reverse happened, so 4.04% seems to be the real current share of Linux on Desktop as desktop clients were read properly/werent spoofed.
Nevertheless, Valve’s work with proton has pretty much crushed the argument that Windows is needed for games. That use to be a major sticking point, preventing people from leaving Windows - but now not so much.
If you play games that requires anti cheat It’s gonna be harder to switch