A highly simplified statement. There are many other types of people.
When homo sapiens conquered the world and supressed the other variants of humans to extinction, this was not done by brute force of the individual, it was not done by higher intelligence, and it was not done by better technology. It was done by culture and stories. The neanderthalers were stronger, smarter and better tool and weapon makers than us, but their culture was limited. They could only manage small family units, while we, the Homo Sapiens could build huge tribes that were bound together by stories and culture.
The bible is a strong collection of stories - millions of people are bound together by those stories. Asking whether the bible is factual is irrelevant - it is not its purpose to convey facts, but to bind people together.