Well, unlike TV/Movies, typically ALL music is available on ALL platforms, so there isn't a service problem. Spotify and others are still really nice to use for consumers.
The app works pretty well but the database it has to use isn't as mature/quickly updated as Tv/Movies. I believe it uses musicbrainz? Either way it's not as standard as the others if feels like.
At least we have Musicbrainz.
But a big part of that problem come from the legacy time.
Just see how many releases were made for old bands like ACDC...