> A city provides a useful analogy. When available land becomes scarce, urban planners initially reduce the spacing between buildings and use roads and open spaces more efficiently. Eventually, however, further horizontal expansion becomes impractical. At that point, the solution is to build upward. High-rise buildings create more usable space on the same piece of land by utilizing the vertical dimension.
It only works for cities designed from the ground up for such density, simply because of all the supporting infrastructure that humans need (utilities, roads, public transport, education, entertainment, recreation).
Retrofits are insanely expensive and often fraught with issues.
Really? someone tell that to my city