This may be the best point that you've made.
We're already drowning in propaganda and bullshit created by humans, so adding propaganda and bullshit created by AI to the mix may just be a substitution rather than any tectonic change.
as one example, imagine if you could churn out a stream of "foreigners are taking your jobs!" articles, but every one talking about a different sector or profession. people would be far more likely to stop and read the article that was talking about their particular line of work, and thanks to ai you can now practically write a custom article for anyone you can think of in as much time as it takes to identify the demographic.
I know more academic/intellectual types who are less willing to, than I do the average joe who seeks answers from all directions and discerns accordingly.