You are dramatically underestimating the difficulty of hunter gatherer life.
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).
I think it's clear though that the ordering of QoL goes roughly:
Wealthy City/Farm > Hunter-Gatherer > Poor City/Farm
So for about a million years most people had it pretty good, then for about ten thousand years most people had it pretty bad, and then the last hundred years or so many people have gone from bad to good conditions, but many still endure pretty bad conditions.
If we could somehow compare the subjective quality of life of the people of Sentinel Island and the people of Manhattan Island I suspect that the least happy Sentinelese folks would be happier than the least happy New Yorkers.
The other comments here are all making absolutist claims - "I can name a circumstance in all human history that was worse therefore your claim is wrong." But that's of course not how humans make decisions - they make decisions based off of what they know and have experienced. The situation in the US today does not lead people to have children in the same rates as the baby boom generation - and that's the difference between positive and negative growth.
Yes, the cold war never ended. Yes, people have largely forgotten about it. Yes, any minute misunderstanding could really blossom into WWIII or worse, still. The fall of the USSR helped US society forget the anxieties of cold war. The cold war also existed in a universe of possibilities allowing for growth the US is unlikely to see again. There were big governmental projects in the recent past (to the cold war) that made whole industries and even cities (see: Las Vegas) possible and flourish where they weren't before those big governmental projects.
The voracity with which they attacked my idea and the exact nature of their attacks shows the cynicism I mentioned in my original comment above. Granted, HN is only a website. But I certainly don't expect every post to be just some bot looking to spread cynicism. People have actually internalized and decided to spread and act upon cynicism.