We didn’t call them AI because they weren’t (and aren’t) intelligent, but marketing companies eventually realized there were trillions of dollars to be made convincing people they were intelligent and created models explicitly designed to convince people of things like the idea that they are intelligent and can have genuine conversations like a real human and create real art like a real human and totally aren’t just empty-headedly mimicking thousands of years of human conversation and art, and immediately used them to convince people that the models themselves were intelligent (and many other things besides). Given that marketing and advertising literally exist to convince people of various things and have become exceedingly good at it, it’s really a brilliant business move and seems to be working great for them.