There’s a fundamental, impossible problem that plagues very tall buildings: the need to move the people upward to the offices. Elevators can only move so fast before you have to start worrying about vomiting and blackouts and broken bones and so forth. Which means that as the building rises, you need more elevators to raise the extra people to the extra floors. The elevators quickly start crowding out the offices or apartments that are the very reason you built the building in the first place.

I spent a fair amount of time in the 1990s working in the Twin Towers, which had solved this problem by having a dedicated elevator that shuttled folks working at the top of the building to the “Sky lobby” on the 78th floor, where they could then transfer to an elevator that served their office. It was just as annoying and ponderous as it sounds. That’s why modern buildings in the U.S. tend to cap out at around 50 stories — not because we can’t build them taller, but because no one really wants to. The view isn’t worth the hassle. The height creates other problems too, from evacuating people during emergencies, to withstanding wind.