It may be that describing our victims as villains (itself such a word) is an adaptive trait.
In that vein, "anyone who downvotes this is a moron"!
People were violent and death was a much more normal thing.
When we look at it in modern time with all our accumulated knowledge we seek to not cause it. Even tyranical and psycotic individuals hold nihlistic or anarchic philosphies.
Truely to understand the worlds pardigm change over history is multifaceted in regard to demographics, and skills aquired, and scarcites and suppluses come into effect too.
cf. The Gnarly Man[0][1] by L. Sprague de Camp. It's fiction, but addresses that facet of potential interactions between hominid species.
[0] https://en.wikipedia.org/wiki/The_Gnarly_Man
[1] https://www.galacticjourney.org/stories/600411gnarly.htm
When human beings began to grow numerous on the earth and daughters were born to them,
the sons of God saw how beautiful the daughters of human beings were, and so they took for their wives whomever they pleased.
Then the LORD said: My spirit shall not remain in human beings forever, because they are only flesh. Their days shall comprise one hundred and twenty years.
The Nephilim appeared on earth in those days, as well as later, after the sons of God had intercourse with the daughters of human beings, who bore them sons. They were the heroes of old, the men of renown.
Numbers 13:32-33
They spread discouraging reports among the Israelites about the land they had reconnoitered, saying, “The land that we went through and reconnoitered is a land that consumes its inhabitants. And all the people we saw there are huge.
There we saw the Nephilim (the Anakim are from the Nephilim); in our own eyes we seemed like mere grasshoppers, and so we must have seemed to them.”
Hostile othering of populations doesn't stop interbreeding among anatomically modern human subpopulations, so I doubt it would between other interfertile parts of the human family.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC368159/
We don't know why, but that would suggest we didn't conquer them, maybe our males didn't find their females attractive enough to have sex with. Neanderthals are more masculine looking than us, so their males would be attractive, but their females maybe looked too much like males to us.
That seems like an extraordinarily unlikely hypothesis, given the mating behavior I observe to be a close analog to the USPS Flat Rate service: "If it fits, it ships!"