I agree with you there. I wasn’t really arguing that there aren’t behavior or addiction problems, however you inserted the word “heavy” and it’s doing some heavy lifting here, and you brought up addiction and behavior which aren’t really the same topic as cognitive decline. The posted article isn’t arguing that there’s a heavy use threashold, it’s arguing that all use of AI is brain damaging. Lots of historical hyperbole about games, TV, and social media did the same.

One confounding problem with the argument that TV and video games made kids dumber is the Flynn Effect. https://en.wikipedia.org/wiki/Flynn_effect