

Likely true by example, but not by definition.
Overthrowing power may be hopeless, but propaganda may still be used simply to prevent the masses from causing slight discomfort to the people in power.
Propaganda is a tool, not a last resort, of the powerful.
I think history is full of rulers who were hated by their people, but were deposed by their peers for selfish reasons, rather than by uprising.
But there is lots of wiggle room in that argument, I admit. My point was more of a technical one than a practical one.
I think that a rigid class/caste system can probably work purely on jealousy rather than on propaganda, but this isn’t based on real world example.