What LLMs lack is consistency. They may build a well researched article about an interesting article, and the next minute write a rambling, disjointed stream of thoughts in a totally different style.

A human mind keeps a personality that keeps generating thoughts in the same direction, unless some mind-altering force derails it. A LLM has no guiding stable personality of that kind, rather has millions of different personalities and which one you get is dictated by whatever information you put in its context window.