It wasn't propaganda and rhetoric which eroded the public's trust. It was repeated attempts by authorities to argue based on their authority, instead of using their knowledge to actually make compelling arguments. When inevitably these experts and institutions got things wrong, they lost credibility because they staked their credibility.

We were never supposed to listen to experts because they were experts, experts were supposed to make good points people would listen to. It's shocking that we've grown so accustomed to crappy institutions that we've forgotten what a properly functioning institution even looks like.