[jvdh]

The life and the work back then is very different from the life and work that we have now. A big factor is that there is no war to motivate people to work hard. Another is that labour circumstances are very very different now than what they were previously.

Finally almost nobody who reads HN does repetitive manual labour. Manual productivity is very different from mental productivity.

From my own experience, I'm not even productive for 40 hours per week. Let alone working 50 hours consistently every week.