This is a big part of why I think LLMs can lead to AGI: humans clearly exist who can think equally well despite having some major gears in their brain going in different directions from each other. If you told me that there was a human who could only think by speaking and who experienced their entire reality and cognition in a textual form, occasionally augmented by flashes of visual or auditory data, I would not be willing to comfortably put an upper limit on their IQ despite all that. I'd just say "yeah, I guess? Weirder things have happened."