I don't have a quantitative way to argue this, but my intuition says that for humans to build something that matches human capability across every dimension would require a breakthrough at the physical level — and such a breakthrough may itself be bounded by the limits of humans as observers.

That said, this goal might itself be a non-goal. AI is going to be — or already is — more powerful than any individual human in many ways. But what my intuition points to is that humans will still have plenty of interesting work to do, like the author's example of handwriting code: it shifts from being scalable value creation into a form of craftsmanship.