CNN reports one in Six American adults believe the earth is flat. Yes, one in six. I think it is more likely that the folks that also believe in talking snakes, living in the body of a whale and an invisible man floating around in the sky taking notes on everyone are more likely to believe this than do agnostics. What do you think? Personally I'm pretty sure the earth is round.
The flat earth model works well over small areas, and is often used by land surveyors. For long-range navigation the spherical model is needed. For geodetic surveys the earth is modeled by an oblate spheroid. It’s not really an oblate spheroid—there are all kinds of bumps and depressions that have to be dealt with.
The point is that our perception of earth is not real and we have to use mental props to represent it as an objective idea or “thing”. None of those models are absolutely true—they are just modes of thought.
For that reason I will try not to judge the flat-earthers too harshly.