First party backups from Apple (iCloud/iTunes) restore a perfect replica of the phone, including app icon locations, arrangement, notifications, offloaded storage etc. I'm honestly skeptical that anyone else would be able to pull that off.
Yes, Apple has private APIs that it uses for its monopoly abuse benefit. That is why Apple's "Music" app can't be deleted from your computer ("'Music.app' can’t be modified or deleted because it’s required by macOS.") but Spotify can be deleted.
The solution is for Spotify to sue them on this specific issue and for other people to sue them similarly.