Our apartment building seems to pre-date elevators (I'd estimate construction as somewhere in the mid-1980s), or at least come from an era when elevators were incredibly scarce. Many buildings in our neighborhood bear evidence of this, as well. Here's how you can tell: add-on external hallways on alternating floors.
Chinese apartment buildings don't have internal hallways. Instead, a small collection of apartments on each floor will have doors opening onto a stairwell, and a building might have four or five of these stairwells. An important part of your address is not just your building number, but which door of the building you use. Neighbors with a common wall often have to go to the ground and exit the building to visit each other.
Back when elevators were rare, instead of building an elevator for each door, construction plans would feature one set of elevators at the end of the building, with stuck-on hallways protruding from the building to allow residents to transit from stairwell to stairwell. And to limit the costs of these external hallways, they only appear on alternating floors. So our elevators go to odd-numbered floors and you then use the stairs to access the other floors.
Our elevators don't share an operating program, and this gives rise to the bane of our building: people on the 13th floor who call both elevators because they're not sure which one will show up first. We live on the fifth floor, and we often watch both elevators go past us to 13, only to come back down with one person in one of them. This would be so easy to fix with just a computer program that could coordinate elevators, like most other buildings have. Just because the hardware is from the 80s doesn't mean the software needs to be, too.
Another inefficiency of our elevators comes from the Chinese nationals who won't ride the elevator with Westerners. If we get in one, they often turn and wait for the other one, or if they get in one and see us coming, they make no effort to hold the door. This blog post about the mathematics of elevator coordination doesn't mention if the algorithm accounts for xenophobia or not. Hey, you have to protect your credit score, right?