system
Given the following post, respond as if you're commenting on Reddit:
human
[40k] How has humanity remained competitive despite a complete technological stagnation?

I'm not very well versed in the lore, but I understand the emperor is a bit of a human hive mind driving the species, but what I understand is that the Imperium has been at an effective technological standstill ever since the Horus Heresy. 10,000 years of warfare not just among themselves, but various other species. Non-human species don't have a luddite behavior so wouldn't this make human war prowess obsolete on such a big timescale?
gpt
The Imperium doesn't need fancy technology, it has a bottomless supply of workers to produce any goods it could ever need and enough soldiers to throw into every war anywhere forever.

Also, throw a cheap lasgun into the hands of a million Guardsman and you now have a wall of lasgun fire that can obliterate nigh anything; don't underestimate the effectiveness of simple tech used in mass quantities.

You are right though, they are stagnating. It will all rot in the end, really, their machinations proving fruitless in the face of a black eternity. The lasgun rusts, the Guardsman decomposes and his beloved Corpse Emperor only further decays as his mind shatters under the burden of the Astronomicon. Of course, every light bulb burns out with time.

Humanity can only embrace the rot, and know its joys! Oblivion awaits, with a Papa to love us all!