Flat Earthers hold their belief because they know something's off about the official narrative and it's the closest they've gotten to the truth. It's the most stigmatized and ridiculed theory, not because they believe in a flat earth, but rather the other truths many have uncovered along the way.
(media.communities.win)
Speculation
Polaris can also be used as a flat earth argument. It can always be seen from the same spot, which indicates that the earth is motionless.
We cannot see for an infinite distance so not being able to see Polaris from the south doesn't necessarily disprove flat earth.
https://youtu.be/IOSW_LAs67Y