This retort doesn't make any sense. Take humanity back perhaps 40k years ago and language did not even yet exist. Our token base was 0. Put an LLM in that scenario and it will endlessly cycle on nothing and produce nothing, stuck in a snapshot in time. Put humans in that situation, and soon enough you get us.
This is like saying that somebody speaking Chinese is just playing the Chinese Room [1] experiment. The only reason it's less immediately obviously absurd here is because the black box nature of LLMs obfuscates their relatively basic algorithmic functionality and let's people anthropomorphize it into being a brain.
If that is the argument though, current AI aren't just autocomplete - because we could reasonably show an AI an image or a video and have them call a tool rather than return text. That'd be comparable to a pre-language human.
> Take humanity back perhaps 40k years ago and language did not even yet exist.
This is not quite accurate. The human lips, throat etc have evolved to be better at producing speech, which indicates that it's not that recent. And that it was a factor in the success of groups who could do it better than others.
It likely started "no later than 150,000 to 200,000 years ago."
sources:
https://en.wikipedia.org/wiki/Origin_of_speech#Evolution_of_...
https://pmc.ncbi.nlm.nih.gov/articles/PMC5525259/