After the last changes made in "Your library", both in the desktop version and in the mobile version, it can be concluded that Spotify:
a) Does not know how to handle a normal music library.
b) It does not want the users to manage a music library in a simple and coherent way.
Spotify, the management of a music library was already invented before you arrived, was created by Apple in 2001, has not changed since then, is simple, logical, elegant, functional and very visual. Without absurd limits, without constant changes.
Essentially: artists, albums, songs and multiple viewing options for multiple types of users.
It's easy, really.