So I was discussing general conspiracy theories with someone and the subject of flat Earth came up. I'm not very knowledgeable on this so I didn't do a great job explaining why someone would think the Earth is flat.

Can anyone give me the main reason why flat Earthers believe what they believe? I gather it's an elite/resources thing to restrict the plebs from some amazing hidden area that is off limits. Something to do with Antarctica?

What are the top 5 reasons people can justify this claim with that haven't already been debunked? I tried to have a look myself but there is a whole lot of crazy out there on this subject.