That is how it sort of works the steam store displays the games the games that work with the deck. You can install other games but you get the a warning that either it has not been testet enough to make sure that it works, or that it is not recommend because that issues with the deck.
This is also my experience. The results are usually very vaguely related with what I search. I had better luck with Wikipedia comparison tables, but often they are incomplete.
I think there is another one that can do both lemmy and mbin but it’s only for iPhones. I don’t remember the name of the the app. Just remembering being mentioned somewhere.
I thought Google had already killed Fuchsia
Local API, not invidious api