Very intelligent people should be able to grasp that a LLM is not intelligent.

Have you tried to "rubber duck" an idea with an LLM. The latest models are pretty damnably good at it.

I have, and I still do this occasionally. I don’t believe the plant on my desk (I don’t have a rubber duck) is intelligent. I don’t need it to be intelligent, either.

I also do it with a LLM every now and then and, while it’s feedback is more useful than a toy’s, it does not need to be intelligent either.

Even intelligent people have demonstrated they are not immune to the damaging effects of AI sycophancy. The most recent example that comes to mind is Hank Green.

Yes, I use LLMs this way, they're not friends, not therapists, not persons, they're tools, like a word/language calculator.