When the twin towers were built, they were excessive (in terms of the need for office space in the 70s). In the down turn, they were considered “pure speculation”. In The 80s though, demand caught up with supply and they were absolutely necessary to meet the growth. This does not mean that every excess of a growth period is necessary, but every excess during periods of ebullience is not waste1.
1. Lamade, T. The end of blitzscaling. (2022).