A brain is an algorithm. Given an unreasonably precise graph of neurons, neurotransmitter levels at each junction, and so on and so forth, one could obtain the same result via pen and paper. It will just take a lot of long laborious effort. That’s ONE reason why brains do not have cognition.

There is a whole branch of AI trying to do this, but they are still at the very initial stages. LLMs are not the same thing at all.