Flat earthers aren't really relevant. People just like to prove them wrong to show others how smart and down to earth they are.
It's stupid because it doesn't take very much intelligence to say the Earth is round, especially when it's more or less common knowledge.
Flat earthers would argue that flight times are all manipulated; e.g. the planes just fly around for the time that matches what would be needed for the fake round earth
It's stupid because it doesn't take very much intelligence to say the Earth is round, especially when it's more or less common knowledge.