The Weekly World News served (serves?) up that sort of nonsense for years, but for the most part the media didn't go around falling for hoaxes, whatever the source. Probably a few deepfakes will spread like wildfire on social media and then the public will start wising up to the technology.
As it is, there are apparently more than a million people who actually believe QAnon is real, despite the fact there is nobody willing to put their name to the source.
https://slatestarcodex.com/2013/04/12/noisy-poll-results-and...
The basic premise - some 4chan shitposter happens to have Q-clearance - is entirely plausible. The fact that anyone can post anything as QAnon also gives plausible deniability for any claim that turns out false, while any claim vague enough to turn out true is taken as evidence.
Conspiracy thinking is extremely widespread and many conspiracy theories are widely believed, such as the JFK assassination, the fake moon landing, or "vaccines cause autism".
It's entirely possible that a secret service agent accidentally shot Kennedy, and they're on the record of saying so.
"We don't know" is not really a conspiracy theory. "We don't know, therefore X must have done it" is a conspiracy theory. Conspiracy thinking is the tendency to make these connections.
Is QAnon actually a highly placed government official (or someone with access to information about the function and plans at a high level)? From all their big predictions so far (arrests etc) being false I think we can pretty easily conclude no.
Are you someone who cannot resist coming up with a counter-argument no matter how thin? You might want to ponder how much value that adds to discourse in general.