With some booms you have something to show for it, for example, a railway network. With others, such as tulips, there is nothing to show. After the predicted b

With some booms you have something to show for it, for example, a railway network. With others, such as tulips, there is nothing to show. After the predicted bloodbath, do we get some infrastructure and products worth keeping at the end of it? If so, does that mean the system can limp on, after even more money has printed, or do we get to another big fork in the road where systematic change is required?