Tribal men share everything: there was no private property within Paleolithic tribes. It’s clear that private property was brought about by agriculture and the end of nomadic life in the Neolithic era. Even a few years ago, the notion of private property was unknown for Polynesians: if you have more than them, they take away from you; if they have more than you, they give you.
Just like the Neolithic and modern diets, the social structures born out of the Neolithic way of life are incompatible with our genetic dispositions and are therefore not sustainable. That’s one more reason why every civilization ends up in collapse.
Tribal men are not members of paleolithic tribes, you conflate the two. Not all tribal men share everything, that is just a flat out lie. Some tribal people may live communally, but most tribes have customs for what property is owned. Gift economies can function like private-property economies, so no currency is needed.. A tribe is just a kinship-based group, a form of large, extended family.
Paleolithic men formed hunting bands, and were the primary providers. Women were of biological necessity forced to care for the young, and limited to hunting small game animals and gathering fruit, berries, edible plants, etc. Egalitarianism is a myth, social stratification the norm. The more intelligent, strong, cunning, etc. would have been given first choice for eating, mating, etc.
Civilization ends in collapse because individuals lose interest in their own affairs, they hand over power to a small group of individuals who promise utopia: free health care, bread and circuses, etc. This socialist utopian thinking comes to dominate a society and then it collapses because no one is producing, there are too many parasites.
It is as if you had a tribe where everyone was the chief, and no one wanted to hunt. It would not last long.