It is fragile because it does not matter - a better lie will obfuscate it quickly.

Let's imagine a simple truth: vaccines are efficient, work well, are tested seriously, produced immense good for humanity for at least a hundred years. Well just find 3 random kids who got autism randomly after taking one and you have entire slices of the population rushing to the lie like flies to a turd, that vaccines are more harm than good. You can brandish the truth a million times, the lie is better.

Truth is fragile, people are seduced by lies, because lies are crafted, they're targeted, they're intelligently designed. They give you what you want, that God decides our fate in this particular case, and that medicine is evil for trying to change it (or whatever is the deeper reason antivax are so desperate for these lies, I really don't get it, I'm more attracted to pro-medicine arguments, even if they are lies themselves maybe). The truth is dumb, simple, inelegant, uninteresting and, quite powerless: we often don't even want to hear about it.

You need countless proofs to even observe the truth. You need nothing to observe a lie, you can fabricate all the proofs you want.

Give me a counter example ? I'm so annoyed at people telling me the Americans didn't go to the moon because a flag was waving suspiciously, I don't believe a truth ever took over a lie now.