One other thing to add: It isn't the elevator scheduling software being obtuse, that software gets a huge amount of thought. But elevators are expensive, and building owners do not over-spend on a whim. Typically, they have just enough cabs (if that) to handle the expected load.
Not only that but different countries have code regimes that make more elevators especially expensive. See how building codes in the US basically ensure there are only two real manufacturers in the market vs a healthy ecosystem in others: https://youtu.be/Or1_qVdekYM