Propaganda doesn't totally rob people of agency free will (more accurate term), if it did this site wouldn't exist. People do have the capacity to develop critical thinking, skepticism, and a basic curiosity about the world that allow them to develop some resistance to propaganda.
You can hold people accountable for failing to even attempt to do this.
Another point I've made on this site: I think we over emphasis the effects of public education. Yeah sure US schools teach a rosey view of US history and don't really teach kids proper critical thinking skills. That's the case in MOST countries with a public education system. And as crap as it is US schools do at least give you access to resources that you can use to further educate yourself.
I don't think we can really argue the average American child is more indoctrinated that a Russian peasant who parents were illiterate, where the only provider of education was the Orthodox Church and who were told from birth that the Czar was ordained by God. People in places with far FAR worse educational standards than the US have managed a clearer view of the world.
the quality of propaganda facing me or facing a peasant are quite different as well. People rejecting the divine right of kings seem more like ex-mormons to me than what the :amerikkka: state and corporate media figured out how to brainwash people constantly and consistently.
This is true but also the quantity of easily accessible counter propaganda is greater than ever.