There is a major discovery problem and saying "out of scope" does not make it go away.
That said, the web has already developed a solution to this issue. It's basically just indexing. It's a very valuable technology, hence why Google got so much money from doing it.
You don't have to get all defensive about RSS, I think it's fantastic technology, but it is missing a few key components to be a replacement for social media in a meaningful sense. I know you know this, because you are here on a social media site right now instead of reading OP's feed. Whereas I don't want to ever leave my reader and instead consume news and recommendations and comments from my friends (of friends) right from there, instead of using gameable/botable centralized platforms with topics and moderators I don't control or trust.
My vision is not clear I know, I hope I can find time to prototype (or at least spec out) what I mean some time soon.