Conspiracies are like an elephant in an open field. If you put a barn over them people will want to know what is in the barn. If you fill the field with fake elephants, some more convincing than others, you can claim all the elephants are fake and to prove it you poke one of the fake elephants. The fake conspiracies hide the real ones. Simple as that. And it works. The people who believe the elephant is there usually fall for one of the good fakes and end up looking like fools. Most people who suspect it have doubt and therefore do nothing about it. And then there are the sheep who literally think they are showing their intelligence by declaring that anything that looks like an elephant is fake.