Short of developing psychic abilities, how would you then address the discoverability problem without relying on a third party?

Forums, search engines, social media, and link aggregators are all third parties with their own ranking. Nobody outside of a handful of small-web hobbyists have put a "cool links" section into a website since 1997.

This is classic engineering missing the forest for the trees.

The answer to your question is: same as we always did before! Do you talk to friends? Colleagues? Family? You definitely chat with us here on HN. All of these people share things with you constantly.

There's a funny obsession in tech circles to gather all the information they can as quick as possible. I much prefer to optimize for the quality of information I'm ingesting.

There’s always a relationship aspect in discoverability. Unless the set is small, there will always be intermediary nodes in that graph that will connect consumers and producers. But there’s no need for it to be a mega tech company. Radio DJs help with discovering musics. Books club can help with recommending books.