What we know is that humans created improved versions. Stronger, smarter, more ruthless and cunning, more charismatic and good looking. And of course, also more ambitious.

Due to their objective superiority they rise to leadership positions in many countries or regions, and start warring with each other for world domination.

I don’t think it is detailed how the normal humans overcome the warlords, but they are defeated and killed / exiled (khan etc) and gene editing becomes illegal for everything but severe birth defects.