… [A] society’s first task: reproduce at a level needed to keep the society going.

I don’t think that is the Categorical Imperative you seem to think it is, for two reasons. 1) cultural propagation is not the same as genetic propagation, and the latter is not necessary to the former; and 2) even if it were, now we are facing existential threats posed by too many people, especially too many people in industrialized societies. So for us to survive for more than another century or two, with living conditions rapidly degrading during that time, we have to figure out how to keep a society running with steadily fewer people.