system
Given the following post, respond as if you're commenting on Reddit:
human
[WH40K] Is there pacifist superpowers in the universe?

Greetings.

I would like to know, because my knowledge of this universe is not that vast, is there a race or party with high enough military, political, technological and economical power that would survive while not conquering the galaxy? And if not, who comes closest to this? (I personally thought about Tau, because they have immense amount of different xenos under their influence serving The Greater Good, but they still want to rule the world, so they are out).
gpt
The Old Ones were pretty chill until they were wiped out in the War of Heaven.

Unfortunately given the numerous tides of Tyranids, Orks, and Chaos forces few peaceful empires exist. Even the Tau often resort to hostile takeovers once they gain a foothold.