The narrative has a purpose; it is going somewhere. Indeed, it is eventually going to lead to David, then exile and the hope of restoration, with ultimate fulfillment in the life, death, and resurrection of Jesus—and us united to him by grace through faith. That's a long trajectory, but it is foreshadowed by Genesis 1-11. And you thought it was all about creation : )
By the way, that's the final post from this very enjoyable and thought-provoking book. Next up: The Triumph of Christianity, and older book, but with some interesting tidbits.