Life expectancy at birth of both humans and Neanderthals pre-agriculture (Upper Paleolithic), is also just over 30 years. That works out to be almost exactly 1 billion heartbeats and correlates well with the regressions, according to those charts.

Given the above, it is kind of amazing how long humans remain fertile, even without modern medicine [worrying sigh - parents just don't tell you these things].

Except "historical data" is not what where we would "naturally" be, since life expectancy is dragged down by high child mortality rate.

Not to be snarky, but what are the child mortality rates for a monkey or a hamster?

This doesn't answer your question, but when we evolved to walk upright a significant level of risk was added to childbirth.

My point is that life expectancy is a useless metric in this context as here we're interested in average life span of a person that survived childhood.