If I understand correctly, there wasn’t much difference in lifestyle between Neanderthals and Homo Sapiens until about twenty thousand years ago. Then suddenly there was an explosion of advancements in tools, weapons, clothing and especially art and Homo Sapiens vaulted ahead.
It’s still a mystery what got switched on in our heads but I guess the alien monolith from 2001 zapping our ancestors and turbocharging their brains is as good as any.
But I personally think they couldn't handle the weather change. And my former BIL is just a hold-over.
/johnny