A human brain has qualities that make it very different from AI, but the same as other living creatures: it's alive, it can feel (sensations, pains, pleasures, emotions) that give it rich experiences and memories, and it hardwired to continue existing and protecting the body it is inside. So: motivation, desires, fears, and continued consciousness and thought without any external person having to poke or prod it into "doing".

None of the models I've downloaded have sprung to life spontaneously, or done anything remotely unpredictable. None of them can act without input. They all have strictly limited ways to receive input and pass output. They aren't alive, can't feel, don't have experiences. The fact that they are a phenomenon that emerge from billions of snippets of our language lets them express languages in extremely convincing ways, and they are extremely impressive in what they can do. But this isn't Short Circuit or D.A.R.Y.L. or the Terminator, none of them have feelings. None of them continue to think after the program exits.

Without those characteristics they can only generate based on what they've ingested. The capabilities are still astonishing, but they're still dead things, and nobody will ever risk their life to protect the model "context" from getting "killed"