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.
I believe the Steam Deck would be a significant portion of the Linux desktops, but Steam’s survey might be a biased source, still
What does significant portion mean to you?