Really? It often seems like the original PageRank algorithm was using links as a measure of content quality and relevance, and now everyone claims they are. But thanks to SEO, we saw that was false (homework question: would it still be true in an Internet where all actors are committed to creating "good" content?). I think links are independent of content quality (or rather search result ranking, because quality is subjective), and we need better AI based solely on page content.