I think everyone knows it's not that no one can lie, its just that number-of-people * odds-someone-breaks-the-lie * time conspiracy would have to be held means that conspiracies that have a lot of people in the loop for a long time are unlikely to go unexposed. A conspiracy requiring a significant footprint of people, money, resources, and generated artifacts can hold for only so long. E.g wartime atrocities involving hundreds of people might hold for a few years, or until the end of a war, but not longer. The lies of the Bush administration could hold long enough to get into war, but not for say 30 years.

Usually this argument is super solid against the kinds of "long running super conspiracies" that people argue for. E.g: - The earth is flat and the fact it is a sphere is a lie told by generation of scientists and elites. 1000s (or more?) of people * hundreds of years. Ya right. - The moon landing was faked and everyone at NASA at the times knew it. 60 years * hundreds or thousands of people * massive resource spend and physical footprint: ya right.