It seems that in today's worldwide economic collapse, only those countries can build relatively stable economies that mine and sell mineral commodities. (Like Australia and Russia.) Most countries have none of these resources. But in the liquid mantel under Earth's solid crust, every mineable element is present in a fairly even mixture. Would it equilize the energy and material production disparity between countries, if there was a budget to develop a deep drilling technology that can reach under Earth's crust? Can we speculate what stops current technology from going this way?
Someday, it's all about cost. Engineering is science where the unit of the last equation is a dollar sign.
Probably the fact that it would be far, far more expensive than simply using what is available at the Earth's surface, recycling what we've used already or substituting something else.
