You've presented a good enough case against conspiracy theorists, but there's another story to follow, I hope, on why conspiracy theorists feel such need to distrust authority and credentialism. We live in a society based on consumptionism and blind faith in the Invisible Hand Job of market economics, where everyone pursues the anthropocentric goals of extracting resources from 'somewhere else' via purchases with artificially lowered prices. Conspiracy theorists distrust the voices of 'authority' because our so-called "authorities" believe in and swear allegiance to imaginary beings and maintain that we live in 'free' markets. A corporation is a group of people who have sworn moral allegiance to a pile of money, and the stock market is collective wagering on that moral turpitude.

No currently accepted civilized (city-based) economic model supports the human animal as a sustainable species in the natural world that spawned us, and that leaves everyone wanting for solid grounding of their mental models. Human brains are pattern-matching devices that support survival in a high-threat environment. When every other person is trying to sell new patterns with deceptive practices, and our children get most of their education from deceptive advertising, is it any wonder that humans are collectively on a dead-end evolutionary path and losing their grip on facts?

You don't need a conspiracy theory when there's a system entirely based on mindless self-destruction.