This is laughable. If propaganda and advertising don't work, then why is everyone so invested in creating it?
The people creating propaganda are also interested in enforcing censorship if they are in the position to do so.
Propaganda and censorship work far better together than individually for groups that want to brainwash society into certain beliefs.
The trick is simply keeping people like that out of power.
But since you go on about advertising, that is a way for groups that want it, is to be able to force people to listen to their message. This robs people of their agency to listen to what they choose to. Censorship also doesn't allow people to listen to what they choose to. This makes advertising and censorship very alike. They both result in a persons loss of freedom to choose what information they get.