Not really, because if you are taking it seriously you're missing the point. Grimdark is black comedy taken to the extreme; it's so bleak it becomes funny from an out-of-universe perspective.
From the in-universe perspective...remember that the typical Imperial citizen only sees a tiny fraction of what we do. For most Imperial planets, 'only war' is a thing that happens far away, and as far as they are concerned/allowed to know, the heroic warriors of the Imperial Guard are winning in their never-ending grind to destroy the aliens. For the people actually under the knife, it sucks, but they're actually a tiny fraction of the Imperium's total population.
As was said to Beorning way, way upthread, there is no 'average' for a polity as large as the Imperium. Between Hive World, Agri-Worlds, Civilized Worlds, Death Worlds, Shrine Worlds, Forge Worlds, Feudal Worlds, and probably a few other categories I've missed, you're going to see an unimaginable variation in what a 'typical' human will experience.