Google Play Music was extremely album-focused, but their move over to YouTube Music has basically scrapped that.
GPM even let you modify the metadata for albums; I had used this to strip out things like "(2020 Remaster Special Gold Edition)" from album names, and to cut "bonus" tracks off of albums (nothing as fun as playing an album and then getting a two hour long spoken word interview with Quincy Jones), and finally to reorganize my classical music so that the artist was the composer and the orchestra/performer name was just munged into the album title (obviously deeper nesting would have been better, but this worked well).
Now with YTM even browsing by artist is nearly impossible, and when you do, it doesn't display the albums by that artist that you've added to your collection, it just displays everything, so there's no real way to avoid seeing 20 copies of the same album remastered at different times mixed in with "pop rock of the 90s" collections. It's just dreadful.
All I want is a music service that lets me access an unlimited virtual store and bring whatever content I want and organize it recursively by tags (i.e. when I navigate to "artist" it presents me with the ability to narrow my search by "composer" or "album" or whatever). I stick with YTM mostly because it came with free ad-free YouTube. There is no public API to talk to the service, though, so I can't even build my own frontend (although there are numerous hacks, most of which involve checking your plaintext password into a git repository, which of course means compromising your gmail account which is essentially the end of the world).
It's really a weird merge, I browse youtube and I see the music I like from Youtube Music there because musics are somehow fetched from YT and not from a different place ( like it was on Google music ).
It seems that if the music is officialy available on Youtube, Youtube Music fetch the music from there, if not it's using an internal catalog.
If you want to avoid their awful YTMusic web UI there are options. There's a decent, standalone, GUI YTM application for KDE [0] which I've used (sadly it doesn't support logins, but if you just want a player it works well enough).
There's also a plugin for Mopidy [1] that lets you listen through your MPD / snapcast [2] server, but that's more fiddly.
[0] https://apps.kde.org/audiotube/