Apple preventing Spotify from advertising their lower prices is just part of the way Apple attempts to push you over to Apple Music. I seem to recall a recent story about how Apple essentially forces you to buy iCloud storage space. Well, they also bundle that with Apple Music. Oh, you're out of space on iCloud? (You will be, since Apple has never increased the available space since launch, just added new and more expensive tiers.) Well, for a small monthly fee, you can get enough space to back up your phone and Apple Music.
Oh, you don't want to pay for iCloud? Well, I'll just constantly remind you that you're out of iCloud storage space until you relent just to shut up the messages.
That in addition to things always launching in Apple Music without any way to change it. Connect your iPhone to a Bluetooth speaker and Apple Music will launch. Press the "play" button on said speaker (or Bluetooth keyboard or the like) and Apple Music will launch. Connect to a car, and Apple Music will launch. Doesn't matter if you're doing something else at the time, even if it's using Apple's own Podcast app, iOS will always launch Apple Music and interrupt it.
Apple is an illegal monopoly and should be treated as such. They're also a trillion dollar company. A $2 billion fine is nothing. It needs to be much, much higher.