Ojo, interesante reflexión:
Be afraid. Be very afraid.
For years, I have bristled every time someone said "they should just break iTunes up," because while, yes, iTunes is bloated and a bit slow and maybe somewhat buggy (and there's a case to be made that it doesn't make sense to have all media in one app), it is also POWERFUL, and I don't think there's anything quite like it (that balances 1) robust local library management with 2) matching/syncing music you've added from any source and 3) a streaming music service like Apple Music). My iTunes library (music, podcasts, TV, and movies) is almost 2 TB and almost 10 years old. I use it for hours every day while I work. And the likelihood that these new apps will be SIGNIFICANTLY stripped of its power features and flexibility terrifies me.
Robust smart playlists; granular ratings (5 star system, and even half-stars if you turn those on like me, lol); lots of editable metadata (including weird but useful stuff like custom sort fields) and track-specific options like start time, stop time, remember playback position (all of which syncs across devices); the ability to change said metadata (plus stuff like album art) even on Apple Music (don't believe you can do that on Spotify, and a surprising amount of my music is incorrectly named or has crappy scans of the art in Spotify); editable lyrics (which sync across all your devices); various highly customizable views (and the ability to import/export playlists, copy/paste list views into spreadsheet apps, etc.); and I could literally go on and on...
Like I said, it's a little clunky (though not nearly as hard to use or navigate as people make it seem), and by now we should have handoff between this and the iOS Music app, etc. and lots of other minor features would be nice, but man, people really don't give iTunes credit for the power user features it has maintained over the years. If the new Music app is a repeat of the Final Cut Pro debacle from years back, I really don't know what I'm going to do...
