True, but now you have a prisoner's dilemma situation where it's to the general benefit to have kids but not your personal benefit. So we're relying on other people's kids, or, as the high-income country birthrates decline and the equator continues to heat up, immigration.
If most people stopped having kids, 401k would be useless. Old people still rely on labour of the young, even if it is abstracted.
True, but now you have a prisoner's dilemma situation where it's to the general benefit to have kids but not your personal benefit. So we're relying on other people's kids, or, as the high-income country birthrates decline and the equator continues to heat up, immigration.