We already have a simpler solution than that, namely the Cesarian section. It hasn't been a safe option long enough to have had a significant impact as an evolutionary force though. Plus, there hasn't been a lot of evolutionary pressure for increased intelligence since the advent of agriculture.

We might be the most intelligent creatures in the galaxy, but that's a very different matter from being near the most intelligent things that could be constructed out of a comparable amount of matter. Natural selection isn't that great a process for optimizing intelligence, it's backpedaled on hominids before given the right niche to fill, so while we don't have a process for measuring how close we are to the ceiling, I think the reasonable prior on our being close to it is pretty low.