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.
likely content blockers preventing the trackers from working properly and invalid user agents. So i would expect about the same ratio of usage on there as well. Maybe very slightly more Linux since maybe the users are more likely to tinker with their browser configs and install content blockers, but even there Id say its an extremely slim minority of even linux users who do that
StatCounter also sometimes miscounts when new versions of windows or macos come out. At one point (I think at windows 11 release) there was a huge dip in windows 10 users and a huge gain in “unknown” and it was quickly fixed.