> Secular humanism, by contrast, emphasizes development of the self, and discourages social enforcement of moral norms
I don't think this statement is true. For example, secular society provides the legal framework that reinforces the social practice of marriage.
> single parenthood rates is the single factor most highly correlated with low economic mobility
Poverty is a much bigger driver behind low economic mobility. Poor people in the west tend to have less stable family structures, it has nothing to do with social norms and everything to do with money. https://www.jstor.org/stable/44127459
> But we are often myopic about the benefits of social structures to the majority
If this means what I think you are saying (please correct me if I'm wrong) that we should turn a blind eye to the injustices fomented by a big religious institution like the Catholic church, because overall they appear to do more good than harm, I would 100% disagree.
The Mormon example is a bit of a weird one. Utah has a higher GDP per capita but I'm not sure you can ascribe that to religious practices. It might be just because Utah is better farmland than (say) Nevada. https://countryeconomy.com/countries/usa-states/compare/neva...