Few, if any, think they are part of any "surplus."
Each has his own purposes, however far his "liberty" will take him in his "pursuit of happiness."
I suppose "we" (the human race) "need" a certain number if we're going to colonize Mars, or perhaps the vast ocean floors which are 70% of the surface of the planet.
Just a thought.
Western society is enhanced by more kids from families who are able to support them through their own efforts. Those who will demand provision from what I've worked for, for the benefit of MY kids and grandkids, I consider a liability.