Then we have to work less and less for the same living standard. Or work on higher living standards.
Go back 300 years and ~3/4 of the population were farmers. If machines take over these jobs, how can our life possibly get better? Today 1-2% of the population are farmers, and see how the world changed.
If no one has money to buy the new machines, then good luck. I think it may be in the implementation of the machines. If replicators on Star Trek are ubiquitous and cheap, then I can see that being an incredibly good thing. But if it's just the rich with the technology, not so good. Seen Elysium?