Yes, this is the essential issue. Any system competent to fully ground and check factual statements in a stream of arbitrary text will be phenomenally more comp

Yes, this is the essential issue. Any system competent to fully ground and check factual statements in a stream of arbitrary text will be phenomenally more complex than the original LLM, and usually will be able to answer queries directly, at which point one wonders what the LLM is adding. I think at best, if we can somehow identify all factual statements that need to be cross-referenced and then offload them to a knowledge base (dubious), we are left this kind of mad-libs connective flow that the LLM has created which approximates the essay style of a human writer. I'm not certain that has much practical value besides allowing for a form of undetectable plagiarism to be published as though it were free-form writing.