According to the StatCounter, Linux on the desktop has continued to rise and remains above 4%, with this being the healthiest it's ever looked on the desktop.
I'm guessing there's a reduced pool of desktop pc users, thus Linux users are now slightly bigger in proportion? There has been big advances regarding Linux adoption, too.
I started using Linux in 2021 never had any problems with drivers for anything. Debian also. It was just a pain in the ass to install until I figured out I had to download the iso with non free drivers or whatever. Glad they made this easier for Debian 12.
Now that I think about it, I actually first used Linux in 2021 too. For me it was because the laptop I had shipped with a HDD that was known for being prone to vibration failure, so while waiting for the warranty request to be approved I was running a persistent Ubuntu live USB
Proton making Linux better for gaming, which was the biggest excuse for holdouts. Steam deck showing you could not only game on Linux, but do so while sitting in a tree, with long term support implied by show of confidence from a large corporation.
Windows steepened its enshittification spiral.
The pandemic put a lot of people in a more experimental space, and they tried a lot of shit. And a lot of people picked up new skills. Including Linux 101.
And people saw authority in general start failing in a big ways. A lot of people started questioning shit. Including corporate hegemonies.
Windows 11 was officially released. That giant spike in late 2021 almost perfectly matched when Windows 11 was released. The Steam Deck was released in early 2022. So, from the graph, I would say the two main contributing factors are Windows 11 sucking to no one's surprise and the Steam Deck exposing people to Linux gaming.