I don't think any modern cognitive scientist believes that the statement "language is the stuff of reason," even allowing for poetic flair, is meaningfully true (and I'll leave aside that humans are, obviously, much more than text generation machines.) GPT-3 can generate text but the only context it has is its prompt; when humans generate text they have their complex situation in the world (and perhaps even non-worldly factors, e.g. apprehension of mathematical reality) as context. Fitting the latter kinds of context into AI models is the challenge still facing the path to AGI.