I would, except there's always some software or some feature missing. And there's always the FOSS app that "might" meet "some" aspects of what native software does but it's almost always never "native" support.
Sure, I know I can play MOST games on Linux, but I know for a fact they'll launch on windows.
Or things like, sure, I know that my corsair Hardware MIGHT be controlled by signal RGB, but what about controlling the pump in my AIO? Or the sound levels on ny headset? Or the DPI in my mouse?
Then you have things like drivers. I'm not using any Nvidia GPUs right now, but the nvidia support for Linux is atrocious and you lose access to things like RTX-HDR and RTX Voice, and hell, even in AMD you lose access to certain features like AMFM2.
Then the software, not only does things like Adobe or Office just don't exist, the FOSS solutions are not industry standard, so sure, I can learn to use LibreOffice, but that's worth absolutely nothing when you apply for a corporate job and they expect you to know how to use outlook as a bare minimum, hell, even the Google office suite is being adopted faster.... Ah, but if the software is available there's still a chance it doesn't work because it's missing a dependency or something and you have to ask people to use the terminal and... Sigh
All in all, it's just behind in many ways, sure, for some people it's ok, and for laptops I'd think is mostly ok, great even. But I know I could deal with Linux, and I don't want to troubleshoot a whole PC to play a game when I already spend the whole day dealing with solving issues or servers or services on my job.
I'm rooting for Steam OS to release to desktops because my living room PC is LITERALLY just for gaming, so that "could" work nicely.
The pump works without software obviously, but iCue let's you change the speed of the pump.
Sound levels of the headset refers to the equalizer profiles.
FSR Frame gen ISN'T AFMF, which is great on older games capped at 60fps where you can easily get 120fps and it honestly feels fine.
and of course I know steamOS is just a distro, but they actually fine tuned stuff for gaming, and like I said, if you're only gaming, sure SteamOS/Bazzite or whatever might just work. But if you use your computer for basically anything else, most people will still have issues.
All of what you described is just EXTRA work people need to know just to play games. The reality is that most "solutions" are always workarounds or alternatives. Most people prefer NATIVE first party support.