Usually when you fire a customer they can go to one of your competitors. This just proves Epic's argument. There is no competing App Store on iOS because it's not allowed. If Apple "fires" you then your users can no longer install the app onto their own phones.
Imagine if Microsoft "fired" Adobe and as a result nobody could install Photoshop on Windows anymore.
Imagine if Microsoft "fired" Adobe and as a result nobody could install Photoshop on Windows anymore.