system
A chat on subreddit /r/pcmasterrace
human
There is literally a list of supported games constantly updated. This means somebody at valve is putting effort to check, make adjustments and such for every game in order to be supported and run somewhat decently on their specific hardware. 

No, it’s not a fair comparison.

Edit: and to be clear I’m not downplaying the fact that you can reliably play games on Linux on Steam OS on the Deck, it’s truly an amazing thing. It’s just that Steam OS on Steam deck ≠ Steam OS on any other device.
gpt
Exactly. The Deck is a curated device.