> One problem with this is people as a group tend to be stupid. What stops the workforce from voting to reduce their work hours to 30 hours per week?

Seems reasonable to me. How much work (both input and output) is required of humans in a society is that society's choice. Many people think that, e.g., American society has a cultural expectation of working longer and harder than is necessary or appropriate. Especially when you could possibly have rebalancing schemes to employ more people for fewer hours each. shrug