I honestly don't understand your point. Humanity is not in danger of dying out from lack of fertility, Dutch (etc.) culture/genetic stock is not in danger of dy

I honestly don't understand your point. Humanity is not in danger of dying out from lack of fertility, Dutch (etc.) culture/genetic stock is not in danger of dying out from lack of fertility, and an argument from eugenetics is both dangerous and likely to be moot when genetic tinkering becomes widely accepted in a couple of generations. (Also, e.g. country-level wealth is extremely non-adaptive according to your criterion. You may want to reconsider it.)