"In 1950, 14 percent of men were out of the labor force. Today, that figure stands at 31 percent."
https://www.nytimes.com/2018/06/15/business/men-unemployment...
If we take 40 hours (and that's less, according to the original article), then this factor alone would make it 31% less for an average man! So 8 hours a day just turned into 5.52 hours, for men at least. It's just that the rest of the time is not spent puffing cigars at the gentlemen's club as Keynes might have imagined, but stuffing your face with hot pockets playing Call of Duty on your aging parent's couch.
However, from the original rootsofprogress.org article, i didn't quite get this part: men aged 20 Work hours Other hours 70,612 (20%) 276,522 (80%)
Ok, so retirement, sure. They mentioned child labor, holidays and education, but for most men aged 20 in the US that doesn't even apply (20 is not a child, number of holidays barely went up on their graph, education is irrelevant for 70% of men aged 20). They don't seem to consider the 31% men checking out of workforce. So what is this huge number of non-work hours that makes up 80% of your life? Guess I have to go read the reference.