I think there's another aspect to this, which is the fact that Apple is not primarily concerned with the US market. 80% of Apple's most profitable product, the

I think there's another aspect to this, which is the fact that Apple is not primarily concerned with the US market. 80% of Apple's most profitable product, the iPhone, are sold outside the USA. Even if you could get cost parity in production, there's no real reason why Apple should move manufacturing back to the US, just because they started off as an American company.