system
Given the following post, respond as if you're commenting on Reddit:
human
(WH40k) Where do you think mankind would be if the emperor never existed?

If the earths human psykers hadn't gotten together and been reborn as the emperor where do you think humanity how do you think things would have gone for humanity?  Obviously they wouldn't be the power they are now but would they be a smaller but still fairly prominent faction like the Tau or a small all but forgotten faction that was long ago wiped out?
gpt
Humanity would have fallen to chaos, and the remains of the empire of the dark age of technology would be just a smaller, weaker version of the eldar, probably with inferior technology to the current imperium.