> That's really missing the point. Recommendation engines are a lot more dumb than you are thinking. They don't understand the content at all. I think you're t

> That's really missing the point. Recommendation engines are a lot more dumb than you are thinking. They don't understand the content at all. I think you're the one underestimating modern recommender systems, especially the ones built by advanced teams in big tech companies. They absolutely use content features. Among other advantages, this counters the cold start problem (how will you learn about a new video if it doesn't get recommended to anyone).