Having your own collection is great. But it doesn’t provide the service Spotify does (or any streaming service). 80% of the time I listen to discovery-type generated playlists. I want to find new music. This is fundamentally impossible with the music I own. This is something you can’t self host. Even if you have a vast collection of music you don’t know (by whatever means your get it), you still need the algorithms to pick the music that you’re likely to like.

I really wish I could. I self host basically everything else. Even tried some local music similarity training for “smart playlists”. It’s kinda neat at best, but no where remotely close to the music discovery of Spotify and other online services. You need the massive amounts of users to derive that data.