multiple and costly military invasions were to offer democracy as goodwill and for world safety.
a certain vaccine I can't dare to name is a vaccine as it does provide immunity.
the institutions of most democracies surely can't be so corrupted.
worldwide cocoa isn't mostly harvested by enslaved workers.
HIV is so far more prevalent in Africa because they can't afford treatment and understand prevention measures there.
JFK.
I could go on and on but not sure how many examples you would need to accept that the chances for enormous secrets known by even a significantly large group to not take a freaking long time before blowing up is rather close to zero. thus reconsidering your opinion on the existence of conspiracies.
and, about shortcuts to making a lot of money being kept rather well secrets: dark budgets, secret and hidden inflation, supply fudging