You're right.

An alternative explanation is that the brain is a Bayesian probability computer that make predictions. In our case, it means that when you hear the beginning of a sentence your brain reckons what's next, before you actually hear it. It allows a dialogue to flow, with less blanks due to the time needed to understand what is being said.

Indeed our brains are productivity champs.

This explanation doesn't need an evolutionary mechanism because everything was there before language. It is just an adaptation to a new feature.

Imho, it is very similar to AI Deep Learning (DL) Large Language Models (LLM). Chomsky's position is interesting but only functional, not material or practical.