There's another element to this that I almost never see discussed. Ideas are not facts. Neither LLMs nor humans can generate new knowledge, as opposed to ideas, by thinking alone. Physical investigation and experimentation is necessary.
The exception being pure mathematics since it exists solely in the realm of ideas. I'm willing to call that knowledge, but it's still a distinction, the old analytic/synthetic dichotomy of Kant.
That conception of knowledge is interesting, but I think using the label 'knowledge' for it is very problematic, it's too far from common definitions. The fact that you have to carve out an exception for mathematics already shows there's a problem. Because if maths, shouldn't thought experiments also produce new knowledge? You're excluding special and general relativity. It seems to me that what the concept actually describes is "information about the world".
> The fact that you have to carve out an exception for mathematics already shows there's a problem.
I don't see how that's an exceptional case. Mathematical theories may not correspond to physical objects, but they still have to be tested for consistency, logical validity etc. As for relativity, one could argue that Einstein's theories were indeed not "knowledge" until their predictions were confirmed (like, say, the gravitational lensing thing). The Michelson–Morley experiment preceded Einstein, but it had to be checked that the theory was consistent with that, and so on and so forth.
The exception being pure mathematics since it exists solely in the realm of ideas. I'm willing to call that knowledge, but it's still a distinction, the old analytic/synthetic dichotomy of Kant.