Apple is Fighting the US Government, and the US Government is Right
Too Long; Didn't Read
Apple is abusing Market Power in a way that makes it difficult to compete on their platforms. Apple may have built the best sandbox but so long as they're allowing others to play in that sandbox they need to make sure the game is played fairly, this same rule applied to Microsoft during their anti-trust lawsuit case. Windows is Microsoft's baby but if Microsoft unfairly promotes their products at the detriment to other competitors then anti-trust lawsuit (as simple as that)