See: "According to Sahlins, ethnographic data indicated that hunter-gatherers worked far fewer hours and enjoyed more leisure than typical members of industrial society, and they still ate well."
Citation: "Notes on the Original Affluent Society", Man the Hunter. R.B. Lee and I. DeVore (New York: Aldine Publishing Company) pp. 85–89. Published in 1966.
The average life expectancy in Africa today, the poorest continent, is over 60.
The average life expectancy of hunter gatherers was about 30, give or take 5 years.
For instance, my understanding is that life expectancy at age 5 in both Africa and the UK are approximately equal.
Right, because of basic modern medical care, which hunter gatherers don't have, often dying of problems with their teeth in their 20s, untreated infections, etc.
And that's only one of a deluge of reasons as to why hunter gatherer life was much more difficult than modern life, even modern life in relatively poor countries.
We can have a debate about whether life is easier in current South Sudan versus prehistory hunter gatherer tribes. Beyond that there's no debate to be had.
I'm just pointing out that the metric you used is pretty deceptive, like the average life expectancy for Romans was mid-30's, but that definitely wasn't the modal age of death (that would have been 0).