My problem with of ADB and crew are righting chaos, is that they are trying to make falling to the ruinous powers as some sort of based and red pilled choice. But when you break down to it, most are in the exact same position they were during the great crusade, or worse off for it.
Like let's break it down.
Death Guard
Forced to pledge to nurgle (still under someone's thumb)
Mortarion is trapped being something he hates serving something he hates.
Most plague marines bend the knee to morty and nurgle, so the exact same shit they were doing during the great crusade.
Emperor's Children.
Fell because fulgrim fell, and Fulgrim only fell because of the influence of chaos.
Now most of them are just serving slannesh mindlessly.
World eaters
Fell because their primarch was tortured by his life and he fucked up his sons.
The few world eaters capable of real thought are merely dealing with a bad situation.
They all serve khorne without question.
Thousands Sons
Fell because they had no other options.
Magnus begrudgingly serves tzeench even when he doesn't want to.
Most of the sons are rubrics, meaning most don't actually think.
Stuck in a situation of serving tzeench even when they don't want to.
Iron warriors
Forced to serve chaos because perturabo had to, or die.
Are mostly the same as they were when they were serving the emperor, so what was the point.
Word bearers
Literally all groomed from birth to worship chaos. This is especially funny because they encapsulate all the fedora tipping propaganda ADB and crew try to fling at the imperium with none of the nuance.
The Nightlords
The first true chaos space marines.
Primarch is dead
They are mostly unpledged
Just go around as glorified guns for hire.
Alpha legion
More information needed
Luna Wolves
Primarch dead
Abaddon serves all 4 ruinous powers and is literally flailing with no plans for anything if he actually wins.
The brotherhood within the legion is gone and everyone hates each other.
None of this is based and redpilled. The imperium of man in the 30k era was a paradise compared to this, thus justifying every loyalist space marine to try and bring the imperium back to what it was.