All one needs to do is look at the correlation to nearly any societal metric in religious societies vs. irreligious ones. Compare the plight of women for instance in Sweden and Saudi Arabia. The effect of religion on these metrics uniformly pushes them in the direction away from human well-being. People will argue that in Soviet Russia, Nazi Germany, and North Korea were atheistic societies, this is far from true as the leaders, as you say, become the defacto religion. This is not an irreligious society. Kim Jung Il's requirements are even nuttier than the popes (e.g., he requires a duvet made of the softest down, which is supposedly the feathers from a sparrow's chin, so thousands of them had to die to satiate this weird requirement). I think the US is a great example of a country completely stymied by a hyper-religious minority. It is a terrible shame that this anti-scientific, know-nothing demographic has wielded its highly disproportionate power in a most destructive way.