I was referring to the fact that building and maintaining housing is still a largely manual process, and requires a fairly large amount of human labor. Maintaining power, water, sewage, and other things required for modern housing requires an even larger amount of human work.
Whether there are enough houses to actually fit all the people is unrelated to this.
Post-scarcity does not refer to the physical resources required to maintain civilization. It refers to the ability to maintain said resources and civilization without a lot of human labor. We could have ten houses per person, but housing still wouldn’t fall under the post-scarcity umbrella until we could maintain and build new houses with minimal human labor.