That's what books were for (among other things): they were knowledge prosthetics. EDIT: And to be clear, yes, books were conveying information from other adult

That's what books were for (among other things): they were knowledge prosthetics. EDIT: And to be clear, yes, books were conveying information from other adults. But 1) the capital requirements of engaging or operating a printing press meant that there was some gatekeeping (for better as well as worse) concerning which adults' views made it into print, and 2) there were things like peer review and other social technologies to increase confidence in the accuracy of the information contained in books, i.e. to make that gatekeeping more than merely economic. LLMs are ingesting the unfiltered thoughts of anyone with internet access, and then noisily producing outputs based on them (with some limited inexpert human fine-tuning at the end).