I think Spotify and other streaming services have a problem very similar to the restaurants. Take an artist with a 40 year career and a dozen acclaimed albums and bags of songs almost everyone loves, and when that artist comes up it is always the same one or two songs. The most played songs, causing feedback and making the problem worse. In my mind, one of the core reasons for asking for recommendations is to discover something different, which means ignoring or maybe even penalizing popularity, because you are likely already familiar with the popular by definition.

I found Spotify surprisingly good at recommending new music. Not amazing, but considering how low the bar is thanks to other services like Netflix I'veveen pleasantly surprised.

For example it recommended a band with just a hundred monthly plays which I loved. Almost all bands it recommends has less than 10k monthly plays, so not huge "safe bets", and most are quite decent.

Netflix's DVD recommendations worked this way. It identified cohorts with similar categorical preferences and recommended content other people in the group enjoyed.