You are missing the point here. Even if humans are better it will require fewer and fewer of them as more and more will be dealt with by sub-algorithms. Also I

You are missing the point here. Even if humans are better it will require fewer and fewer of them as more and more will be dealt with by sub-algorithms. Also I dont thin you realize little magic there is in imagination. Computers can dream, thats what it requires to imagine. The rest is just about finding proper context that fits humans needs, but even that is learnable by machines. So the question you should be asking is what mystical human ability is imagination that it can't be done by machines. But again even if it was always outside of human abilities it wouldn't require more but less developers over time.