We do know how LLMs work, correct? We also know what they are capable of and what not (of course this line is often blurred by hype).
I am not an expert at all on LLMs or neuroscience. But it is apparent that having a discussion with a human vs. with an LLM is a completely different ballpark. I am not saying that we will never have technology that can "understand" and "think" like a human does. I am just saying, this is not it.
Also, just because a lot of progress in LLMs has been made in the past 5 years, that we can just extrapolate the future progress on this. Local maxima and technology limits are a thing.