But an assembly line manned by robots? Why should that be cheaper in China? Is capital that much cheaper?
Even if wages and other costs were equal, the location advantage is substantial. It's not that it's cheaper in China, but that it's cheaper in the huge manufacturing hubs. You have suppliers and manufacturers for just about every single component you need without long-distance shipping, and a deep pool of design and manufacturing expertise working in the area.
That's not to say you can't manufacture efficiently elsewhere (we have plenty of recent examples such as the Raspberry Pi), but that the advantages has as much to do with the concentration of resources as with the cost of labour and regulations. And of course, as this inudstry becomes ever more automated, it no longer matters much for jobs where it happens any longer.