>None of that is possible without massive changes to the structure of the building.
This is addressed in TFA. There was one building the profiled architect designed where they spent the $$ to turn the elevator core into a courtyard. He was able to add back the "lost" square footage as additional floors, which made the project profitable enough to build out.
Addressed in the article! Apartment buildings need less elevators than offices since residents tolerate longer waits. There's still elevators, just less.
This is addressed in TFA. There was one building the profiled architect designed where they spent the $$ to turn the elevator core into a courtyard. He was able to add back the "lost" square footage as additional floors, which made the project profitable enough to build out.