The iPhone is not a store. The App Store is a store. Epic wants to be on the iPhone, but not necessarily in the App Store. Ideally, Epic wants to run its own store on the iPhone.
In any case, App Store is the only store in town, where the "town" is the 1.5 billion iOS users. If there's only 1 store, with no competing stores, that's an entirely different situation legally.
In any case, App Store is the only store in town, where the "town" is the 1.5 billion iOS users. If there's only 1 store, with no competing stores, that's an entirely different situation legally.