My previous laptop couldn't boot linux for like 2 years until kernel patches came out. It still to this day doesn't support bluetooth in linux due to an unfixed/wontfix kernel bug. And the wifi only uploads at 1mbps under linux.

By incompatible I don't mean "won't boot at all" (even though I've had that multiple times, including with my Surface tablet), but it's all the little stuff that often doesn't have a 100% working driver (either yet or at all). Maybe you don't experience this but there's still lots of people that do.

Personally, every game I care to run works perfectly fine on my Steam Deck

Almost none of my TeknoParrot games work under linux, no matter what version/patch/fork of wine/lutris/proton/etc. I try. Plus there's tons of people that still want to play those newer games with kernel-level anti-cheat, even if you don't.