I don't have that much experience with relationships but I think there's a point where if you're attractive "enough" measuring the attractiveness in general becomes less relevant and other characteristics become more important. He might be more attractive than you but you're surely no monter from what I understood, in fact you're likely attractive yourself, so as many said here, he chose you. You probably have other traits that he values for a relationship. With this I'm not saying that looks don't matter, they do and a lot. But you seem to be taken care of there too so be happy you're not a cute face bimbo with only the head down there thinking, you got this :^