It’s the variable reward that does it. That’s also true for animals. Give a pigeon a button that when pressed gives sometimes nothin or some food and they go haywire and become addicted to pressing the button.

Then the money men saw it works the same in humans. Hence loot box mechanics everywhere. Press bottom and get variable reward. Whaddya know, some folks are really susceptible to this and hit that button like a pigeon.

Sports betting is the same, but with the illusion of skill around it.