Let it go man, he answered you over and over and over and over already. Your so-called "simple question" has turned into an interrogation.
So my understanding is that there aren't any features or traits that he feels the iPhone does better in his opinion than his gs7 edge. He keeps it because it's different. Ok then. If that's his feeling so be it. I've received some pretty good clear and concise answers from others so I'm not sure why it had to feel like an interrogation. But if that's his feeling that's fine by me.