Take something like Flat Earth Theory. Okay, if that's real, how can you do something different and gain benefit from it? Can you create an airline service with quicker flights to certain destinations?
I was just reading a conspiracy theory about how the The Great Pyramid was actually a device to change the magnetic poles. Okay, can we recreate it to change the poles again?
What are some conspiracy theories that if true can actually lead to us doing something different? How can we benefit from knowing the "truth"?
First let me preface by saying that the truth is its own reward and pays dividends even if you don’t recognize how/why.
Sure, let’s assume the world is flat. In that case the maps that depict a globe, are wrong. Through exploration and cartography you can fix the maps and likely find more land / places to go than are currently known to exist. I liken it back to the pilgrims... What did so many of those europeans do when the maps were updated to include a “new world” where they could escape their miserable lot in europe?
No, and that is also not a conspiracy theory. That’s poor fiction written by hacks.
Though, let’s play devil’s advocate and pretend it was true, or had sufficient (or how about any) evidence to support it. The answer to your question would be yes, and the fact that we can’t do that and no one has any idea how the pyramid could accomplish such a miracle would serve as strong evidence / ostensibly prove that the “theory” is bunk, or that we have no idea how to replicate it. If we read a history book saying hydroelectric dams generate power - do we automatically gain the ability to build one ourselves? Even if we can’t build one, does knowing the truth about them not benefit us at all in your view?
There are too many to mention (though many, if not most, are not conspracies nor theories. They are falsely labeled that way to discredit and suppress them).
Take the moon landing hoax / nasa money laundering/embezzlement scheme. You could organize and share the truth to stop the tax dollars being stolen and wasted! You could do lots of stuff - the question is really, “Will you?!” Our enemies hope (and conspire so that) the answer is always no.
Let me rephrase and see if you think your question is still reasonable, “How can learning new correct things and/or identifying and discarding untrue things we learned in the past ever benefit us?”