There is a sign in the Prora Museum that mentions briefly how the planners and engineers of the Prora Nazi Holiday Resort knew that contemporary infrastructure technology was incapable to serve the planned massive building complex with the required services (fresh water, sewage, food, waste disposal, heating) if it were ever completed as depicted by Kraft durch Freude propaganda.
They knew the project will fail the moment actual people were to use it at scale.
But the mere fact of building and showing off a construction site was a propaganda success for leadership demonstrating will power.
Nothing to learn from that for current events, I guess.