If you think I am legitimizing flat earthers you really don't get the point. I am just saying that for 90% of people belief in this or that mostly dictated by people around them.

> unknowable metaphysical topics

religious people often conveniently shift goalposts to make sure what they say is always beyond knowable. We launched satellites and found no heaven above? fine, it exists in some other way. No soul detected? our technology is not good enough. Flat earthers do almost the same thing just they use conspiracy theories instead.

If you want to find a difference between religion and flat earther theory, Christianity for example (not sure this applies to all religions) is supposedly helping humans live together better, like: be kind, do to others what you want be done to you, don't steal/kill/rape etc. But that's not really related to how it's proven or factual.