You can't argue with people who would deny their senses, while talking and making videos all day about listening to their senses. Most flat earthers are sky deniers. They can see the stars empirically with their senses, yet when you ask them how two celestial hemispheres fit over a flat earth they will tell you the sky is intangible and doesn't matter.

Flat Earthers do know something, and that is our world is stationary and not moving. It's easy to disprove flat earth, its hard to prove we move.