So the two training sets are completely orthogonal, and the well educated renaissance man is somehow able to take a very small exposure to written words and do at least as well as GPT(n) in processing them and responding.
The renaissance man is very obviously not working solely based on a few years of reading books (or learning to speak/write).
Ah! you cry. Don't humans have some sort of hard-wiring for speech and language? Perhaps. But it is clearly completely incapable of enabling an untrained human to deal with written text. Does it give the human a head start in learning to deal with written text? Perhaps (maybe even probably). It demonstrably takes much less training than GPT(n) does.
But that is sort of the point of the comment at the top of this chain.
For example, it might take several paragraphs to wholly capture all the meaningful information in one image in such a way that it can be reproduced accurately. Humans, and many animals, process large amounts of data before they are even capable of speech.
The data GPT-3 was provided with pales in comparison. It is unclear whether these GPT models are capable of induction because it may be that they need more or better sanitised data to develop abstract models. Therefore they should be scaled up further until they only negligepbly improve. If even then they, still, are incapable of general induction or have inaccurate models. Then the transformer model is not enough or perhaps we need a more diverse set of data (images, audio, thermosensors, etc).
You're ignoring the insane amount of sensory information a human gets in 30 years. I think that absolutely dwarfs the amount of information that GPT-3 eats in a training run.