Working in software makes us take things for granted. Everything should be optimized for maximum efficiency and the best user experience.
In a building with multiple elevators, with each of them have it’s own calling buttons, but all the elevators are on the same routing system for maximum efficiency: Suppose you have the two elevators on the same floor, for simplicity the ground floor. You push the up button for one of these two elevators. I expect the closest one for which I pushed the button should open, reality this is not the case.
It turns out, elevators are hard coded, if the three elevators are on the same floor, and you want to go up, a specific one will open no matter which button you pushed, which for a lazy person as myself isn’t the best experience.
Elevator makers don’t have to think of this. At the end there is no bounce rate, & conversion is 100%. No one will decide to take the stairs because the wrong elevator opened.