Both misinformation and disinformation have been rampant since the dawn of media, yet people tend to believe everything they read. As Knoll's Law of Media Accuracy says: "Everything you read in the newspapers is absolutely true except for the rare story of which you happen to have firsthand knowledge." I doubt the proliferation of even more misinformation via AI will change that.
On the other hand, I do think that humanity always finds a way to adapt, even if it's not the most ideal way. I'm not as optimistic as you, but not as pessimistic as the doomsayers.
Somewhat fittingly, I was unable to find a reliable source for Knoll's law aside from a 1982 NY Times article[0]. Perhaps even the law itself is a fabrication.
[0] https://www.nytimes.com/1982/02/27/us/required-reading-smith...