Everyone who wants to find fault with modern constructions trots out the Second Avenue Subway as an example. This subway is an obvious route for convenience and as such was first proposed more than a hundred years ago. At that time analysis of the geology and hydrology along the route as well as the very large amount of infrastructure including other subways already in place resulted in the conclusion that a subway along Second Avenue would be unreasonably expensive to construct. The idea kept being proposed every couple of decades or so and the conclusion was always the same: Far too much complication and expense to reasonably construct. Then in the 90s politicians decided that miraculous new tunnel boring technology would solve all problems and make a subway along Second Avenue easy and cheap to construct. This new technology turned out to have some complications and as a result all the nearly hundred years of cost estimates stating that a subway along Second Avenue would be unreasonably complicated and expensive to construct turned out to be true.
It is to the credit of our modernity that the project was completed at all. The real lesson here is not one of generalized slowing, but of a lack of rational analysis, particularly when a wealth of information is available.