Consider this...

DWINDLING RESOURCES

The new tech and devices that characterise the 21st Century all require rare earth metals to make – an average smartphone has over 60 “ingredients”. That’s putting a strain on the planet’s natural resources: in China, where 90% of the world’s rare earth metals are found, it’s estimated that its mines will run out in the next two decades – and good substitutes for those materials are hard to come by.

-BBC.com Future Now: 10 Great Challenges We'll Face by 2050 by Brian Lufkin, 13 July 2017