-Also, I can't save a collection of favorite tracks in any meaningful way. I can favorite them, but they quickly get lost in the mobile UI if I do too much of that. I end up relying on global search every time I want to revisit a song or artist.
You can use playlists to save collections of tracks
Sure, but that's a workaround not a feature. I personally don't consume music in playlist format (on Spotify or wherever else). It forces me to still remember "oh yeah, playlist A has those few tracks from XYZ artist".
I'd prefer to have a screen that can sort my saved tracks in a meaningful way.
You can use playlists to save collections of tracks