I think Apple's uniqueness is that it used the fact that it invented the iPhone and for quite a long time had the best user experience in it, to create a very strong brand, and even if android achieves similar user experience(some say it did in kitkat/lollipop, other say with large screen phones) ,Apple's brand advantage will still offer a huge protective moat around some segment of the population.

BTW, modularization is also supposed to offer faster time to market, and we've seen that with large screen phones and Apple's slow response to them(probably because it system was integrated ,hence harder to adopt to a different module).