The embedding layer in an llm deals with much more than the meaning. It has to capture syntax, grammar, morphology, style and sentiment cues, phonetic and orthographic relationships and 500 other things that humans can't even reason about but exist in words combinations.
Cognition is not purely semantic. It is dynamic, embodied, socially distributed, culturally extended, and conscious.
LLMs are great semantic heuristic machines. But they don't even have access to those other components.