From the New York Times
For Mr. Cook, the focus on Asia “came down to two things,” said one former high-ranking Apple executive. Factories in Asia “can scale up and down faster” and “Asian supply chains have surpassed what’s in the U.S.” The result is that “we can’t compete at this point,” the executive said.
Sounds like the same reason people move to cloud-based hosting and services. Fast scaling, and support services. Replace Asia with AWS and it reads as well.