Really because at least 4 times a week a plane leaves from Sydney Australia and approx 12-14 hrs later lands in Santiago Chile.  Of course these two cities are on OPPOSITE sides of the flat earth map.  This makes the flight IMPOSSIBLE on the flat earth map (commercial airlines do not have sufficient range to fly that distance non stop).  Since these flights do happen all the time we can confirm it is impossible for the earth to be flat.

Of course this has been pointed out many times along with countless other proofs but you're obviously to sick in the head to understand basic common sense.