I often wonder what kind of work actually happens at Spotify. Pretty much every major change to the software or api since I started using it has made the product worse. Breaking libspotify, pointless UI redesigns, obvious, user-facing bugs that go unfixed for years. Removing features like play queue for long periods. There's metadata errors and even audio corruption in some albums that I actually reported to them yea…
For better or for worse, Spotify has a lot of customized playlists. At some point, the “workout” playlist playlist stopped being a regular global playlist and started being one customized for individual users.
Their “keep playing more like this” functionality that takes over after the playlist ends is quite good, as is smart shuffle which will mix in tracks that “belong” in the playlist even.
Some songs will play artist uploaded music videos when you play their songs. Their “now playing” widget now shows a larger album art and background information about the band.
I don’t know what happened to the lyrics all of those years, but I’m guessing it was a licensing issue. A random add on is different from first party application support for all of your users, globally.
It’s possible you don’t use any of this and think it’s a waste of time. That’s fine. I think Spotify is seamlessly stitching in extra functionality in non-annoying ways, which I like.