I don't know exactly what is wrong with Spotify, but years ago, I subscribed to Pandora, and it made all sorts of suggestions based on what I liked that revealed great music to me.

But when I wanted something specific, it often didn't have it, so I switched to Spotify because it seemed to have a much larger catalog.

Unfortunately, the recommendations were no good, so I just listened to the same stuff I had played on Pandora, plus specific things that I found elsewhere.

Then I quit paying for it because I didn't feel like I was getting a lot of value.

I have no idea whether either is any good these days, but I would firmly classify Pandora's recommendation engine as highly useful back in the day, and Spotify's as...not.