I mostly agree, but the whole worked only 15 hours a week stat is almost certainly not correct. It came from a paper that only counted time outside of camp as work, so time spent in camp processing food wasn't counted. The actual number of hours varies massively - seasonally and geographically - but probably closer to 30-40.

I'd bet that a lot of that in-camp work didn't feel excessively laborious when it was done while socialising within your group, and without a sense of "wish I was playing video games". Sitting around a camp fire now whittling away at something is more mucking around than chore.