Earlier quoted context omitted.
Yes, but this is only because Apple designed the phone that way. Apple should not be immune from antitrust law purely because they decided not to allow competition.
They do allow competition. Build your own phone and your own app store.
The whole argument is that Apple is leveraging the position in one market (hardware) to gain advantage in another market. Your answer is "competitors can always build their own hardware" don't you see that this is a nonsensical argument?