To see, for instance, the argument that wage costs actually aren't even the main reason for all the outsourcing to China - supply chain issues are. Intellectual labour can be transported across the globe at no or negligible cost, but any element that is to end up in an iPhone will require physical transport, if the next step in the production process is to take place somewhere else. And if you have a good number of such transports, that cost is going to start adding up fast - container shipment is essentially for free between China and the US if you're talking such high-tech products, but it's also slow and time is money as they say. Silicon Valley itself is a good example of the advantages of clustering industry, but Silicon Valley mostly does the kind of work (nowadays, anyway) that could in fact be transported at little or no cost. For a product like the iPhone, having most of your suppliers close to each other is far more important. And that gives an advantage to huge countries like China, which can also redistribute workers on a scale that allows the rapid creation of such huge clusters with all the extra manpower they need, without the titanic efforts it would take in the US or in most other places.