[gwerbret]

Music discovery -- or discovery of movies, TV shows, love interests, or anything else that caters to human preferences -- is an enormously challenging problem that those whose business it supposedly is to solve have largely given up on. Part of the problem is exemplified in this thread: there are endless different ideas of what the ideal $ITEM discovery algorithm should do. Even if the Spotifys of the world were to deploy some modern AI-based tools to fix the problem, the level of tweaking each listener/watcher would need would be so extensive as to belie the entire effort. So they don't, for at least 2 reasons:

First, it's hard, as we all know.

Second, it turns out that the "best $ITEM discovery algorithm" accolade doesn't pull in that much extra revenue. It's far better (for them) to use people's expectations of such an algorithm to profit from a bait-and-switch. As an example, see Amazon's search engine.