How Much AI Is Really Used in Video Games?

How close is the relationship between AI technology and video game development? From the exploratory adventure of open-world games to the comforting loop of online slots, the majority of video games use AI in some way, shape, or form; be it NPC interaction, enemy behavior, or otherwise. Contrary to its portrayal in most forms of entertainment media, AI isn't restricted to robots and supercomputers. Instead, it's a relatively ubiquitous technology, especially when it comes to gaming. As a matter of fact, you could go as far as saying that AI and video games likely wouldn't exist without each other.