If machines can produce every useful good and service better than humans -- including manufacturing copies of themselves -- then the global economy (denominated in units of currency) might be under threat, but people will materially prosper. It's not dollars or euros or renminbi that people really need. People need goods and services. If the machines-do-everything technology gets invented once, copies will soon spread globally [1].
The real problem is more likely to be the transitional turbulence. If self-driving vehicles do wipe out millions of truck driver jobs in the year 2029, but automated doctors aren't ready until 2059, large groups of workers lose income without seeing deflationary relief in the prices of services they need.
[1] The spread of maker machines could happen "legitimately" -- Gates Foundation or a similar organization financing freely shareable re-implementations. It could also happen "illegally" -- a government in a poorer country will just decide to tell international patent/copyright holders to pound sand in favor of their own domestic constitutents. This would be similar to South Africa's treatment of HIV drug patents in the 1990s.
The real problem is more likely to be the transitional turbulence. If self-driving vehicles do wipe out millions of truck driver jobs in the year 2029, but automated doctors aren't ready until 2059, large groups of workers lose income without seeing deflationary relief in the prices of services they need.
[1] The spread of maker machines could happen "legitimately" -- Gates Foundation or a similar organization financing freely shareable re-implementations. It could also happen "illegally" -- a government in a poorer country will just decide to tell international patent/copyright holders to pound sand in favor of their own domestic constitutents. This would be similar to South Africa's treatment of HIV drug patents in the 1990s.