Consider the audacity back in 2007 for Apple to believe it could pull this off. How would they ever make back the R&D to build out a team and pay for expensive silicon designs over the long run, never mind design comparative performing chips? Well today we know. Apple makes nearly 100% of the profit in the entire smartphone space.
It's amazing to think about the advances that Apple are making with their chips and how it is powering their lead in the mobile space.