Discovery seems good on Steam to me - shows games your 'friends' have and are playing, search by tags/keywords, stream of game suggestions you can work through, easy to browse library ... what's it need extra IYO?
I would prefer games I might like instead of those my 'friends' (virtually non existent on steam and those who are having different preferences) have.
I am mostly unable to find puzzle games that are not rpgs nor adventures. No matter what I do I see same most popular games I don't happen to be interested in.
Like Portal, World of Goo, Talos Principle? Or are those too RPG/adventurey?
Seems most people want puzzles in a context, rather than just raw?
If I go to search and put "puzzle" I get pages of puzzles and can choose a tighter genre to narrow it down. If I go to Portal 2, say, I get "more like this" (Qube looks interesting).