system
A chat on subreddit /r/pcmasterrace
human
the point is that even a multibillion dollar company can't get Linux gaming to the point where it's viable for many people. I almost exclusively play steam games, but many of my favorites dont work on either Linux or the steam deck.
gpt
Microsoft is a pure OS and "extension app" company that's been in the business for decades now. Valve just recently got into it, and took a ton of work from other people 'donated' throughout history (legally through open source licensing) and made their own version of it. 

I wouldn't expect Valve to be able to compete from the start over the course of a few years so I don't think you have a solid argument. 

A lot of it is also the problem of proprietary nvidia drivers that constantly lag behind Windows releases unless its for server software.

I do understand that linux is a niche market and most game devs do not care about the steam deck &amp; linux because its not even a penny in a mall waterfall pond compared to ps5, xbox, switch, pc, etc.

In the end, use what you want, who cares. Linux is the best for some things, Mac is best for some things, Windows is best for some things.