Very interesting article! I wrote on Peterson’s recent debates with Harris and I believe while yes, religion has been a great vehicle for social and moral evolution, we now know that such benefits can be divorced from religion.
One can adopt the beneficial moral teachings from religion without needing God or a church, whereas it is harder to have organised religion without fundamentalism and extremism. The weight that God has in seducing one to such beliefs is a heavy one, and if your holy text doesn’t disavow slavery, why should you?