User blog comment:James12708/Possibility of a Mass Effect 4/@comment-6599851-20130419200032/@comment-8419211-20130427002335

cuz I think, when leviathans create an AI they gave to it kinda a mission to save organics in Milky Way. so basically, leviathans didn't ask AI doing the same mission in other galaxies. plus closest galaxy way to far from the Milky Way. I mean, they need to go to other galaxy, build a mass relays. Do not forget, that reapers will lose a lot of ships fighting in 2 or more galaxies. Reapers mentioned that they are infinite, but we know that's not true. Finally, simple logic. Reapers are not curious, what is going on in other galaxies.