The natural end state of marketplaces and social media is the eventual shift from user generated supply to professionalized supply/content. They can fight it for some time, but eventually there is no other way to keep scaling (or prevent power users from peeling off)
Still, as Baszucki made clear, the goal is still actual social networking: surely that will always be better than interacting with an AI! Or will it? It seems to me that perhaps the most important constraint on the web — to actually interact with people as if they are, well, people — disappeared a long time ago.