There are countries with cheaper labor now than China; it seems like a large part of the appeal is having such a robust supply chain for everything you need nearby. That will be harder to replicate, although Apple has the resources.

This is still nothing compared to the slavery in America - we kidnapped people, tortured them and literally bred them so the cotton industry could flourish. If this is what it takes for a country to become a superpower, China is well in its way.