Apple's spat with Epic is actually Epic's spat with Apple
Apple has been providing a platform, iOS, since 2006 that has evolved now into a set of distinct and related platforms: iOS, iPadOS, and tvOS.
Microsoft provides a platform called Xbox.
Sony provides a platform called PlayStation.
Each of these platform providers extract a commish from vendors selling software-based experiences on said platforms.
Why is Epic getting on Apple's teets but not MS or Sony?