And yet, the human brain is still (way way wayyyyyyyyy) more capable than the LLMs at the actual thinking. They're as wide as an ocean and as shallow as a puddle in a pothole. And we didn't need to read all of the internet to do it.

As for the "write a book" part, the LLM will write a book quickly sure, but a significant chunk of it will be bullshit. It will all be hallucinated, but the stopped clock will be right some of the time.

No humans have this scaling capability? What do you call the reproductive cycle then? Lots of smaller brains, each one possible specialized in a few fields, together containing all of human knowledge. And you might say that's not the same thing!, to which I reply with "let's not kid ourselves, Mixture-of-Experts describes exactly this".

Agency may be better understood as Michael Levin's approach where e.g. a lifeform is something that can achieve the same goal using various methods (robust).

Having said that, you can now simply move the goal posts to say that while one human cannot read that much in that amount of time - the collective of all humans certainly can - or at least they can approximate it in a similar fashion to LLM's.

Since each of us can reap the benefits of the collective then the benefits are distributed back to the individuals as needed.