The Dead Internet Theory reminds me of a minor bit of flavor from a Neal Stephenson book, Anathem. In it it's mentioned that this far future civilization (which has seen civilization broadly collapse from technology zeniths a couple of times) had to abandon their set of planet wide communication networks because people intentionally set up computers that would put out huge amounts of information, but all of it was information to mislead, manipulate, obscure, deceive, or convince you to pay money for something. This was done so much that effectively all information, and all actors which might share information, became adversarial on the broad internet, so it stopped being usable.