I’ve watched some of these flat-earth videos for entertainment and education the other day.
These people have taken conspiracy theories to new heights. They don’t even believe the Earth is round, and that there is a mass coverup going on by NASA and all the world governments.
Your question is revealing, however. Why do you think we depend on Antarctic explorers to know Antarctica is a continent? Do you think the only way to know about Antarctica is crunch around in the ice there?
What I wonder is what they think about Lake Pontchartrain.