This is interesting for a couple of reasons. One is that this is about as much market share as Mac ever had at its peak, and almost twice as much as it has currently. Another is that, if you click the link for the site's Steam Linux Data Tracker, you can see that English-only Linux market share (a crude way of filtering out the ebbs and flows of Chinese players on largely-identical hardware and operating systems) is more than 6%, up from under 2% just 5 years ago. A lot of people are unhappy with Windows in general, and especially 11, and Windows 10 is about to force the issue in just a few months as it loses official support. I have a friend whose computer is still in decent shape for gaming but with TPM settings that don't meet the minimum spec for Windows 11; at some point, he'll lose compatibility and have to throw out an otherwise perfectly functional machine, so it's good that some other OS is shaping up to be a good enough option for many people.
This has been an upward trend since slightly before the release of the Steam Deck, as you can see on the graphs, and I've come across YouTube videos from both James Lee Animations and PewDiePie about how they got to be so sick of Windows (and Adobe) they both switched to Linux with middle fingers raised at their old workflows. Folks like them making videos like that can have real effects on the market. Linux has been my daily driver for gaming for about 8 years now, and it's matured so much in that time that I've hardly booted to my Windows partition for any reason. It's not perfect, but if I'm choosing between the quirks that Linux has by accident and the deficiencies that are in Windows on purpose, I'll take LInux every time, and it seems like more people are coming to that same conclusion.
No doubt the biggest remaining frontier is live service gaming with kernel level anti-cheat, but if Linux becomes a larger user base, as it's doing right now, the developers making those games will have to solve that problem to reach that addressable market, and everybody wins.
I'm still a windows guy unfortunately, but I'm getting very excited about the adoption of Linux lately. I think steam OS has been huge for Linux adoption, as many gamers are probably willing to make the switch but only if they can keep gaming without having to use wine or something. I personally run windows only because I have no time in my life to play with computer stuff and just want it to work for me in the hour or two I get in a week max to game, and it seems like we're just about there. I think my next build will be Linux based at this rate! When I had more time to faff about with crap (a couple years ago) I ran Linux a lot but it just required too much intervention to make things work and nowadays I'm far to busy to spend my precious time ironing out headaches.
I was you until about 3 months ago when I discovered Microsoft sells cloud services to the IDF. Political motivations aside, I would encourage you to try out a KDE plasma linux distro. It's laid out pretty much exactly the same as windows 10 and bazzite worked for me out of the box even with a relatively rare gaming laptop build.
I appreciate the advice! I'll try that distro next. I'm hoping after this winter I'll have more time to mess around with my PC. I have a bunch of old parts (fx6300, 750ti) from a gaming PC from decade or more ago that I plan on setting up in my garage for reading PDFs looking at wiring diagrams playing music etc. That will certainly be a Linux build and if I like it on there might put it on my zen3 rig. Currently reading diagrams off my 15 in laptop screen in my garage, will be much nicer with a desktop hooked up to a monitor and a spare TV I have kicking around.