Sure, a lot of them are trolls, probably almost all of them at first. But the problem with pretending to be an idiot is that actual idiots will rally around you and take heart.
Have you seen Beyond the Curve, the documentary about flat-earthers trying (and failing) to prove the earth is flat? You'd need pretty strong evidence to convince me that everyone in the film was in on it.
There is also the tendency of mentally unstable people not getting the joke and more or less taking over the meme. Then the profit-seekers and cult leader types emerge, and suddenly what was a joke is a movement. On a much smaller scale the same thing happens with satirist news outlets, and the process is:
Outlet makes a joke (for a real example “Joe Biden is refusing to leave the White House and has armed and barricaded himself.”)
Joke is spread devoid of context, still as a joke.
Trolls get a chuckle by posting it to some extremist group.
Extremist group doesn’t get the joke and adopts the narrative, fitting it into existing ideology.
Pizzagate and QAnon are great examples of this process. The other process is that schizophrenics dig up old ideas to fit their current delusions, such as “Orgone” and “Chemtrails.” Some of these ideas fit into the delusional ideation of non-mentally ill groups and it becomes a widespread conspiracy theory.
Note that this can all be very profitable, if you look at people like Glenn Beck, Alex Jones, and David Icke.
Have you seen Beyond the Curve, the documentary about flat-earthers trying (and failing) to prove the earth is flat? You'd need pretty strong evidence to convince me that everyone in the film was in on it.