My most favourite conspiracy theory is that ALL extremely stupid or easily disprovable conspiracies (flat earth, moon landings, etc…) are a CIA psy-op to make people dumber.
It's so dumb it goes all the way around to actually kinda making sense.

Well, if you flood the world with batshit insane conspiracies it discredits everyone that's actually on to something. There's certainly some fuckery going on behind closed doors and some folk have caught wind of that but if everyone thinks their nuts because of things like flat-earth and lizard space jews then they powers at be don't have to worry about the public wading through the madness to find the truth. Quite a solid tactic to be honest