I don't understand these blog posts. Unless you're an absolute beginner, what is so hard about doing any of these tasks yourself or reviewing AI output?

AI won't think for you. It just (sort of) does work you delegate to it. It's from this perspective that you might get productivity gains, but the human in the loop is still the bottleneck. This doesn't mean you remove the human. It means the human decides how much they need AI.

There is no AI workflow that removes the human and magically does exactly what was intended. That's wishful thinking.