This article does not mention the release of the SteamDeck at all. I wonder if this could have had an impackt on Linux usage large enough to see in trends like these or if it's just a drop in the bucket.
* not every Linux user plays games or uses Steam, but probably almost all Steamdeck users use Steam.
* StatCounter numbers are based on website views. You can browse web on steamdeck but it's not very convenient, so I guess that, unless it's their only computing device and they have connected external monitor and mouse, most steamdeck users do most of their web browsing using their phone or computer instead of steamdeck.
Linux is market leader once you bring in mobile, embedded and so on.
So no laptops? Isn’t Steam Deck really just a generic PC with a different form factor? Could (and should they even) StatCounter easily filter out the data coming from it
Some data I found on the internet suggests Apple ships about 6 million Macs per quarter, and they're at around 15% market share in the stats linked here. Other data I found on the internet leads me to guess Valve has sold around 3 million Steam Decks in the 2 years since they launched.
So my guess is that if you factored Steam Decks into this they'd account for about another 1% - very roughly.
Servers are a case apart because especially for Windows they have the same UI as desktops even if Microsoft has a no GUI option now. I believe that nearly all Linux servers are command line only.