First of all. Calm down, chill out. Relax.

I didn't once say anything negative about cooperation, I didn't even use that word once. What are you talking about? Why are you building this strawman of cooperation and then dismantling it for me when it has little to do with what I said?

It is a false belief people have that ancient man was overall more altruistic, they weren't. They did not experiment, they engaged with what worked. Cooperation is definitely key to our survival but bigger than that is our ability to weigh risk vs reward and more often than not the more important part of that is risk. Sometimes abandoning an injured ally, allowing the weaker individuals to perish, to abandon the place you call home and other selfish, sociopathic choices were the decision that would lend to one's further survival. Which is probably why we have so much selfishness in our society, not in capitalistic society, but in all societies. It is part of the human condition, people are selfish and rude and protect their feelings more than anything else. Literally most of therapy is people learning to not engage with those knee jerk emotional/mental responses that reinforce these behaviors.

While you can say cooperation was a big part of humanity's success it actually wasn't the big one. The big one was risk vs reward being able to plan and just overall decision making. Which unfortunately psychopaths tend to have the edge over the regular person for, which is why they probably have been routinely successful at survival way back in ancient times and today. Game theory shows us that cheating actually can benefit you especially in the short term and most of human history, for a specific person, is short term. Game theory also shows us it is kind of full of shit, according to game theory the prisoner's dilemma should end in disaster. In practice, it really doesn't work that cleanly. Game theory relies on humans basically being heartless reptiles, which people aren't because they like to cooperate and be liked and engage in kindness and respect.

So I don't really understand the point you're trying to make or why you have an issue with what I said. History is messy, but what is clear is ancient man was not overall altruistic, it wasn't paradise and people/society today is overall completely better.