The Industrial Revolution and labor movements are what got us down to a 40 hour work week. The current (fiat) power structures are what keep us here. If I had 20 extra hours of leisure in my week, I could learn a craft and become more self sufficient, I could study new subjects, I could exercise more, I could be more involved in my community, I could raise a stink at city hall. Instead we live in a system that gives us just enough leisure time that the most efficient way to use it is to opt into the convenience of consumerism. We've been conditioned to keep up with the Joneses. It's not necessarily innate human nature. It's a rat race that keeps the poor poor, squeezes the middle class dry, and secures power for the upper echelons of society (who don't seem to have much trouble coming to terms with their extra leisure time). As long as they can just keep printing money and never be held accountable, we'll keep getting squeezed to do more for less.