From a business standpoint I think they would be smart to follow Netflix's lead. I don't know how accurate it is but people say Netflix uses all their analytics to drive their content production. I can easily see Spotify using all the data on which songs people listen to all the way through and which they turn off half way through to try to make some computer written hit songs.

Of course Theodor Adorno would turn over in his grave when that happens (as if it basically wasn't already happening).

They have been. It may just not be completely visible beyond their Live at Spotify recordings (which, from the copyrights on those albums, I imagine Spotify still has to pay close to the same royalties for).

https://www.musicbusinessworldwide.com/spotify-is-creating-i...

I think they have already? https://open.spotify.com/playlist/37i9dQZF1DWTUm9HjVUKnL

Absolutely, signing artists and acting as their label and main (exclusive?) distributor could work out pretty well for them.