The argument works even if no public parks are built. The point is that a higher number of people ("society") profits. They can hire more workers for the same m

The argument works even if no public parks are built. The point is that a higher number of people ("society") profits. They can hire more workers for the same money because workers are not busy building the statue. More people are getting their own needs met, versus a single person getting a very expensive need met. Intrinsic value is not created by spending money, it's created by people doing work for that money. The right question to ask is "whom are they creating value for", not "how many papers did they get for it".