If you think A and I think B, I am allowed to say B without proving it to you. You can say that my claim is unsupported but by insulting me in a parallel thread you learn nothing. Be open-minded and assume that what you see in open is not everything primarily due to different compute capabilities available to different actors.
Above, AlexCoventry mentioned a paper. If you would like to find more, go to Google Scholar and find all papers which cite that paper. This would be just a part of the whole story since bigger datasets and models are not in open. The progress rate in this field is incredible.
> The Battle of Austerlitz was the decisive French victory against Napoleon
It didn't even catch that Napoleon was the leader of the French. And this was when it just generated text of similar size as the input. Based on just that paper I highly doubt that this method will generalize to creating entire books.