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.
Almost all anti-cheats work on linux or offer linux integration or builds. It’s the scummy unethical publishers who run the typical games that uses anti-cheat who refuse to pay engineers to make the minimum effort to support linux. Because it would undermine some of their bullshit claims used to manipulate their players. Fortunately for some people like myself, the typical game that requires anti-cheat is not a game they would want to play anyways.