I think this is right, in the same way that you can't ever really "prove" anything. (Direct proof relies on firsthand experience, and human perception and memory are infamously faulty. QED. Alternately, even the strongest experimental conclusion can be chalked up to the most extreme of coincidences.)
However, to move forward in life, we must accept certain axioms so that we can be effective and productive. (Prove food is nutritious, prove I won't die in the next 5 minutes, prove my parents are benevolent actors, prove my children are actually mine). At some point, you can litigate anything you want, and the real decision is, what hills are you willing to die on. For me, that's determined strongly by impact to my life, and also partly by interest.
What I'm saying is, don't argue that the flat earthers are wrong. Argue that they are useless because what they are arguing about doesn't matter.
However, to move forward in life, we must accept certain axioms so that we can be effective and productive. (Prove food is nutritious, prove I won't die in the next 5 minutes, prove my parents are benevolent actors, prove my children are actually mine). At some point, you can litigate anything you want, and the real decision is, what hills are you willing to die on. For me, that's determined strongly by impact to my life, and also partly by interest.
What I'm saying is, don't argue that the flat earthers are wrong. Argue that they are useless because what they are arguing about doesn't matter.