It'll be no more or less a transformation in society than the steam engine and industrialisation, things will change, some for the better, some for the worse. Overall I'd say it'll be for the better since the increases in productivity and problem solving will free up more time to do more things.
Discussion
What’s behind your optimism that we won’t become the horse? If it does only that then I agree it will be similar to those past horizon.
Are we operating on different assumptions of what the AI feature horizon is? I’m anticipating it increasing human productivity until it doesn’t need us, and then simply outcompeting us at all thought-based work so as to make human thought work a novelty yes, but not a significant part of the economy. I would agree that it will increase earth’s productivity, but that‘s a goal that I’d say isn’t worth maximizing at the expense of human productivity / population.