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.
It is. I use it as such regularly. Keyboard+mouse+screen = browsing firefox as usual. Works quite well. Libreoffice, okular, signal desktop… I’ve used worse computers in recent years, steamdeck desktop experience is better than many 4 to 5 year old cheap laptops with win10 or win11.