I think his interest is just in seeing what he can make by himself with what he can gather from nature, rather than specifically in replicating neolithic technology. In that framing it makes sense to push at the limits of what he can do even if it's not the most practical way to solve that problem. He knows he can run a furnace and make neolithic-level things with it, so why not see if he can go for something a bit harder? Historically it was solved with a bunch of teamwork, sure, but he's not trying to re-enact history.