I don't understand how a company this successful, that obviously has talented programmers, can't seem to find decent UI/UX designers. I'm not talking about how things look, but the actual design of the user interface and the user experience. 

There are no functional sorting tools for playlists (not within 1 playlist, but across all), different platforms for the service have different sorting defaults, and the search functionality in each of them all work differently. Why can I sort Alphabetically on mobile, but not actually do anything with my playlists once they are sorted as such, other than play them? Why is it that when I search for something, I can't choose to limit my results to just my library?
There is no reasonable way to sort for actual reorganization of playlists. How? How is this an issue for a service that is 12 years(?) old?!
Additionally, why haven't record labels been turned into a usable tag? I assume it's used in algorithms, but why can the subscribers and users not utilize this as a tool to sort and find music with?

While algorithms have improved and the skinning of the UI has become more sleek, I feel like basic utility has been overlooked.