Let's say computers come for most of our jobs. This may not seem likely at the moment; computer scientists and economists offer wildly varying ideas for how deeply automation will affect future employment. But for the sake of argument, imagine that within two or three decades we'll have morphed into the Robotic States of America.
In 1928, John Maynard Keynes famously suggested that within a century technology would have evolved to the point that a 15-hour working week would be the norm in Western countries. A nine-to-five job would become a relic of the industrialised past.