Imagine a person taking a test. This person has the power to look at everyone else's answers, and the power to quickly choose or calculate the answer that is the most common. This person will probably score well above average on the test (though probably not as high as the top score). This person is not smart, but powerful.
A CPU that can calculate a zillion additions in a second does not understand those calculations, much less be able to come up with mathematics in the first place. It is not intelligent. It is powerful.
ChatGPT is supremely powerful in its ability to generate "answers" that are the amalgam of hundreds or thousands or millions of answers or statements made by humans, but dumber than a bag of rocks.