Chomsky introduced his theory of language acquisition, according to which children have an inborn quality of being biologically encoded with a universal grammar
https://psychologywriting.com/skinner-and-chomsky-on-nature-...Yes, maybe we can reproduce that learning process in LLMs, but that doesn't mean the LLMs imitate only the nurture part (might as well be just finetuning), and not the nature part.
An airplane is not an explanation for a bird's flight.
Nature, for an LLM, is its design: graph, starting weights, etc.
Environment, for an LLM, is what happens during training.
LLMs are capable of learning grammar entirely from their environment, which suggests that infants are too, which is bad for Chomsky's position that the basics of grammar are baked into human DNA.