"Agriculture is where I see the fastest impact of AI in low-income countries."

As we've seen with Haber-Bosch (synthetic fertilizer) it will just allow the population to expand until we're up against the resource limit ceiling.

I don’t think so. I think we’re past the point of rapidly increasing population in most of the world at this point (aside from sub sharan Africa which will change soon as well). I don’t think the current low birth rate has anything to do with a resource cap.