This is a classic case of Amdahl's Law[0], with square footage as the commodity being optimized rather than computational resources. The more "efficient" you make the scalable quantity (square footage directly allocated to each occupant in this case), The more dependent The final number becomes on the non-scalable terms (square footage of shared spaces like restrooms, stairways, hallways, eating spaces, and etc). Even a simple double loaded corredor with shared restrooms like a high density college dorm layout has a significant fraction of its base determined by the nonscalable spaces.

Nowadays anyone involved in high scalability computer processes is familiar with these concepts but in the 1960s when Amdahl first started focusing on the nonscalable processes the idea seemed as crazy as these square footage numbers seem to non-architects.

[0]https://en.m.wikipedia.org/wiki/Amdahl%27s_law