You are right that it's possible for one person to support a family. For most people working in the tech industry here on HN they could probably figure out a way to do it. But is it realistic for all families everywhere to be able to support themselves with just a single worker? If it were so simple to achieve, we would not see child labor. We would not see any poverty at all. Clearly we are not yet at the point as a species where we can enjoy a post-scarcity or job-free utopia. We could certainly be doing a lot more to work towards that than we are, though, and I think that's a more interesting point of discussion than looking back through rose-tinted glasses on a few decades of post-WW2 America.