Just boot the computer, choose which DE you want to install
Yeah, that’s not at all accessible to the average consumer; they don’t know what a “DE” even is, much less why they should choose any over any other.
Very, very few people want to deal with something other than a ‘just works’ situation.
I think it will continue to rise. People are updating their rigs all the time. Whenever they update their rig they’ll have to ask themselves whether they want to continue with Windows on their new rig, or try with something new.
The vast majority of this increase is from people playing on Steam Decks, which run on Linux, not from people switching to Linux on their PCs.
If it continues to rise, this is the reason. The general public is less and less into using a desktop at all as time goes on, much less running, and much less changing to, an extremely niche operating system on one.
EDIT: The previous sentence is actually more of the reason, upon further reflection. The total number of people playing on desktops period is falling, and the vast majority of desktops are Windows, so non-Windows OSes will comparatively gain ‘market share’ as that happens, even if their numbers don’t change at all.
The vast majority of the increase, is what I said. In other words, I’m saying it wouldn’t be nearly at the 3% mark without those users, and with over a quarter of all Linux users coming from the Steam Deck userbase, that is, in fact, true.