It's more of a hobby than a daily driver for someone that games on PC games ranging from the early 90s to modern games. Too much hassle when I just wanna install and play.
Yeah steam deck is awesome I have one as well and it got me to dabble with installing Linux on my laptop but there was just too many things that had to be done to get it running how I wanted. You're selling it massively short by saying one command rules all. For instance, my laptop has an igpu and a desktop 2070 in it and Linux wanted to constantly use the igpu by default in games and it wasn't that easy for someone that doesn't use Linux that often to find a fix for that. I have a kid and a fulltime job I dont feel like configuring crap when I get home to have less time to play ya know?
I've honestly had better luck with retro games on Linux than windows. Half the time lutris can auto install the game with minimal input, and patch the games etc - and even with abandonware titles I just pointed proton at them after installation and no issues.
If you're on older integrated graphics however, I will admit it can be a lot more problematic.
My recent experience with gaming on Linux (just switched from Windows for the first time last year) has been nothing short of amazing. I never expected everything to work as well as it has. It's kind of crazy actually.