I did some consulting over 20 years ago to the elevator company that everybody would guess the name of. I spent a week coding with the PhD they had hired to use AI in scheduling banks of elevators (my expertise was the real time embedded OS). His job was to minimize power costs - even if it meant a longer wait for users. His second goal was to handle emergency situations well (fail in well defined ways or operate in well defined ways if there were a fire.) So the high-end elevators are very efficient - for the real customers, the wealthy building owners.