Anti-vaxxers have hurt many people, but maybe you didn’t mean them when you said these people".
Flat-earth belief likely has secondary unwanted effects, like how all conspiracy theories eventually funnel into anti-semitism. It’s also a huge opportunity cost.
This is idealistic, but I think for most people conspiracy stuff is filling an emotional need. If the experiment fails, the emotional problems remain. Thus the theory will be updated to uphold the feelings.
So like if they see a photo of the earth from space, they’re more likely to say it’s a fraud. Truth doesn’t matter. Feelings do.
Anyone who cares about facts on this topic would have left flat-earth after a short while on wikipedia.
So the question is: what emotional need is this filling, and how can it be met more safely?