I view Discovery as a social problem where the content you want is almost always clustered between a relatively small number of creators, regions, etc.

Technically it then becomes less of an indexing everything problem and more of a find a few cornerstone creators, say Khan academy, and occasionally branching out.

So to answer your question I don’t thing the cost/benefit for automating discovery is much better then spending 20 minutes and finding enough cornerstones to fill you for 100+ hours of content. Or similarly finding a social group like an rss feed, say in ios development it would be fatbobman, and sourcing it from there.

Time to source content isn’t the bottleneck worthy of software solutions, yet for monetization reasons discovery is the vice grip of social media and made to be the most important thing.