Physical infrastructure is more than just roads, and bridges. Fiber optics, and safe homes that people want to live in are both huge economic gains. The real secret to infrastructure is balancing utility with the cost to maintain vs simply building them. Unfortunately for China their demographics are in a rapid transition so they are going to be force to invest huge amounts of capital in new homes simply to keep up with changing customer demands. The US is facing similar issues based on long term energy trends, however that's a much more hypothetical issues so it's hard to predict what needs to be done.