The reasoning in this post is completely backwards: just because a job could be completely replaced with a rock without affecting the majority of cases doesn't mean that the actual practitioners of that job are either completely useless or are themselves on autopilot.

Siskind assumes the latter and reasons towards the former, which isn't aligned at all with what actually happens in the world: we do predict hurricanes and exploding volcanoes, and there's no particular evidence that the average doctor is ignoring their patients. We're all subject to biases and fatigue, but neither of those supports the claim that we're all phoning it in all the time.

Edit: I will also note that "when nothing happens at all, a person can be replaced with a note on a rock" is not an interesting statement to make. Dressing it up with eloquent prose (and he is indeed eloquent!) does not change this, and does not a poignant observation make.