Except it isn't. There is no fundamental technical limitation that prohibits Apple from allowing third party app store. It's only because of their arbitrary policy.
This simply isn't true, the market is too diverse to make any assumption like you just did. Some do upgrade based on "hardware specs." Go ask your mom what mhz are. Yea, I'll wait.
iOS is the large reason people choose iPhones over Android. The phone is simply a portal to iOS.
Without the OS the phone is essentially a brick. To argue the hardware is the only product is an absolute falsehood.
The App Store didn't exist before iOS, it was created for it. It is not a separate product.
None of these questions get you anywhere. You made the claim that hardware was why people upgraded - which is false because of the diversity of the market and the fact that the hardware is only a portal to what they want. You haven't dealt with the argument - that the App Store is a separate product from an iPhone. It isn't.
Google Play is allowing Epic to do it. Fortnite is still on the Google Play store.
(The writing has been on the wall and Google is already adapting - they sent out surveys last month to some developers about dropping the 30% fee and charging developers an annual listing fee instead - possibly also fees for bandwidth/storage used like a hosting company does. The survey also mentioned plans to spin off the Google Play store as a separate non-Google company.)
Aha, saw that myself an hour ago too. Wish I'd downloaded Fortnite now when I could. Thanks for the correction.
The Google survey I received specifically asked about experiences as a developer with the Epic Store, whether I thought customers would pay a subscription fee for access to the Play Store & Android updates, and whether I would trust the Play Store & Android if they were no longer owned and run by Google/Alphabet. So it will be fascinating to see how the court rulings change the tech landscape.