Well I think that there are some more or less serious issues that tend not to be adressed by society because some people created huge conspiracy theories around them and everyone sees it as a joke.
Take for example fluoride in waters. It should be a topic to be discussed and we need more reasearch on what it does to human health but now it's just gay frogs and Alex Jones memes.
"Secret" societies with huge influence on nations... that's a thing. Here in Italy we had this thing called the P2 (its members were arrested) wich had plans to push its own political agenda on the governement. It's not even a conspiracy theory, it's history.
After all if a group of people has economic, mediatic and political power there's not much it can't do.
Some other theories of course are total BS, like Flat Earth, Hitler having escaped in Argentina, and pretty much all religions.