> “There are a lot of things we don’t know, but it is not magic. . . . [I]n the end it’s all electrochemistry.”

That’s an element of a belief system you may choose to subscribe to, not a fact. It can’t be a fact because there’s no way to prove or disprove it.

> “My point that even in the case of a ML model, you cannot get an exact reproduction any more than you can get from a human’s memory.”

Not quite. ML models can and do memorize and regurgitate near-exact features of the inputs. It’s not the goal, but it happens.