Question about Steam Deck vs Gaming PC

I have a Steam Deck, and I love it. It can handle 90% of my library, and it's always improving.

I decided to try out a linux distro for my OS, because the biggest drawback has always been the hoops that I had to jump through to get games up and running. I went for Pop OS, since that seemed to be natively friendly with NVidia, and the lowest barrier for entry. However, in Steam, I see that there is a much more limited selection of games compatible with my system. Is there a way around that, to get the same selection as my Steam Deck? Or is it this way because the Steam Deck is a singular platform that is developed for based on specific architecture?