Chuckles - sounds like an opinion...
Most of the evidence is long gone so most everything about the distant past is opinion. However war and human evolution are continuing and those with a sound religion have a competitive advantage. Religion also provides a competitive advantage in business, sports, and life in general. In some cases it can be measured, for example sports teams from religious schools often outscore teams from secular schools once other factors are adjusted for. Team sports such as American football are really practice tribal warfare. Religious families have more children and more successful marriages then secular families.