"They are not suggesting new, very interesting melodies. They are finding you the tweaked versions of the songs you already like and, even on your first listen you can predict the melody that’s to come."
I really don't think that's the main method of Apple Music or Spotify to create a list of suggestions. From what I know, (beside of dark marketing-patterns) the suggestions are created by checking what other songs people like/listen to who ALSO like/listen to this current song (or other songs you played), and the common neighbors of those songs in other playlists.(If you play music for your toddler, your future suggestions will include children's music not because it sounds similar but because "a critical mass of other people who listened to Baby Shark on repeat also listened to: Old Town Road")
It is weird and it’s ironic that they call that “discovery”, as it feels more like variations of what I'm already listening to.
This indicates that the persona that this platform created for you is quite homogenous and probably matches closely with many other personas on the platform, so many people who listen to the same music as you do apparently listen to _nothing else_ than this kind of music...(not trying to defend those suggestion algorithms, just analyzing the comment)