Gregory's Server
Provenance of human written knowledge comes from a lot of places. Just because something was written by a human doesn't make it accurate or non-garbage. But the labor cost in producing misinformation that's hard to distinguish from meaningful writing in the same domain, together with a lot of systems we have in place, makes evaluating provenance a tractable problem.
The ability to produce unlimited amounts of plausible-looking garbage at essentially no cost, and to crowdsource that kind of vandalism to millions of randos by disguising it as something fun, destroys that capability. It's a DDoS attack on written knowledge.