I hear what you’re saying, but there’s a counterpoint to this.

In prehistoric times, population densities were low. In mesolithic times (hunter gatherers) there were simply no concentration of people large enough to wipe out or to do the killing. Nothing could be called genocide at this time.

In neolithic times (the first farmers) violence was definitely a part of life. Some early towns do show signs that they were destroyed. But again, population densities are low enough that the scale of violence would not be enough to call ‘genocide’. It’s a town burnt down with everyone murdered, not a ‘people’ - whatever that might mean at this time. This is not about egalitarianism - it’s population density.

However as we move to the bronze age, there are definitely signs that large scale events occur that might fit into the modern concept of genocide but archeological evidence is severely lacking. The main line I would argue is that the male lines of the neolithic farmers in Europe are hammered and almost completely replaced with the Yamnaya Y chromosomes across a huge expanse - from the east european plains to the Iberian peninsula. Genetic continuity with the neolithic farmers is maintained though indicating that male newcomers were having children with local women, and very few male locals had children. During this event the culture changed hugely - burial patterns, material goods, etc.

I don’t know if we can call this genocide - at least the full modern concept - because these changes took centuries to roll out across the expanse of Europe, but they speak to local conquests and, at the very least, the newcomers prevented local males from having their own families. At worst you can imagine a constant expansion of this new culture taking control of new areas, killing the men, taking local women as concubines and eradicating their gods, customs and ways of living. Quite a lot of genocidal checklist items ticked off there.

By the mid to later bronze age, genicide is definitely a widespread thing, recorded in many texts.