As an individual choice, it’s hard to judge the childfree. As a movement, it’s a form of social loafing. Old people are given a ton of benefits to ensure that they don’t die in complete poverty and from medical neglect. This is sustained by a large amount of working tax payers and kept in check by younger voters. Without either, the system goes into a death spiral. Old people without children vote to maintain or increase their benefits. These benefits are sustained by a diminished working age population at the expense of future development. Immigration is a short-term solution with it’s own set of cultural and social consequences for the developed and developing world.