>One interesting interpretation is the ratio of people with desk jobs consisting of 50% (or higher) fooling around vs sweaty manual labor jobs has led to the average American perhaps only working 20 hours a week right now.

For actual work, maybe even less.

But not having pocession of your body for 8-12 hours every day in exchage for a pay-check, is work too. Even if you just sit there and "do nothing".