Most domains have some kind of internal consistency/theory building you can do. A smart person can certainly notice inconsistencies when trying to learn something. In fact they're likely to be points of confusion that the smart person will dive into just to try to make sense of things, even if they don't suspect the LLM is at fault.

Why would a smart person go to an LLM for an answer they cannot judge or test, be succeptible to flattery and sycophancy rather than picking up on the emotional manipulation and being suspicious/sceptical of the interaction, or looking for support from an echo chamber rather than a Socratic opponent?

All of those sound like flaws and defects of dumb people?

No evidence but somewhat of a counterpoints:

Smart people know LLMs confabulate and tell them they’re Absolutely Right! Smart people don’t want to be embarrassed by trusting the hallucination machine and revealing their gullibility to others.