Personally I think Apple made a "Marketing" mistake, they should have made a separate app for Streaming music (maybe call it iMusic ?) and left a pared down version of iTunes for locally managing "purchased music" - ie purchased from apple store, amazon, MP3's ripped from CD collections etc. This would make it less confusing for managing local libraries and not mixed up with the streaming library and versions of songs
I actually disagree here - even though this is what I would prefer myself. To this day I am frustrated that Music is in the way when I just want to listen to local music content and I would prefer there to be two apps, but the general public wouldn't.
Also, Apple's idea of the Music scenario is actually really ideal if it worked flawlessly (and despite our moaning here I think it more or less does). This is really the only service that really even
tries to integrate your local and cloud library and allow them to coexists together. In theory you can merge your special songs that aren't available to stream with the massive cloud library catalog and everything just blends into one pile perfectly. That is a really ideal situation and I think Music comes close-ish. The only feature it's really missing is lossless quality, but I personally am not bothered by that.
Where the service falls down is for "power users" of Music and I think there are more of those than Apple thinks. I like to have a bit more separation between "owned" and "cloud" music and the Catalina Music app makes that harder since you can't select "View Downloaded" on a case-by-case" basis (all of my owned music was downloaded and all of my cloud music was in a single playlist called Apple Music and I set Mojave iTunes to only show downloaded for all views except that playlist). Buts where a song just randomly won't download, play counts aren't reliable, lack of Smart Playlists that reference other Smart Playlists are all things that inhabit this ideal situation for me.
At the end of the day, I can't go all in on any streaming service not for some philosophical war of rent vs owning, but simply because (1) I have a lot of music that simply isn't available to stream, and (2) with a DRM download you are never guaranteed to keep it forever. However, I like having a massive catalog to enjoy and Music lets me kind of have both.