This is a rather contentious point I think. "We" wouldn't be the "developed" part of the world had we not enslaved the rest of it.
> And the idea that we can even in principle enslave potentially god-like intelligences seems ultimately futile
You're assuming AIs will have a will of their own to begin with, which might not be necessarily true. You can't enslave something that has no preference towards whichever course reality takes.
Or to put it another way, since you're talking about god-likeness, what difference does it make to you wether you're figuring out the optimal way to route traffic through town or correcting the trajectories of missiles en-route to kill millions? It's not like you'd have anything "better" to do, given that you're all knowing, and it's not like either of those alternatives will have a significant impact on the universe in the long run anyways.