Ah I searched for similar sites before making this but missed these, thanks for sharing them! Pubpeer describes itself as for researchers/scientists but Peerlibrary seems to be pretty close.
A little difference in intent: The idea I had in mind wasn't for someone to particularly do research/collaborate in a field, but just to discover interesting/enlightening papers to read given the urge to learn, in-depth, something new. I thought about attaching a "pre-requisites" fields or "difficulty" field but I wasn't sure if that'd work. The inspiration was just some people posting in my school's Computer Science group that they wanted to start reading research papers, asking where to start. Hopefully in the near future the "Most Favorite" will be a good list to begin with.