For most of them nothing is real, neither the stars nor the planets, and any mention of those things before modern days was planted by the shadow government or something. Some even think the moon is fake too and the sun is some kind of big light bulb in the sky or whatever.
More than believers, they are deniers, of everything.
I'm definitely not a Flat Earther, but I watched a documentary about them and a lot of them seem to think the Earth is flat and the sky is like a glass dome, and the other stars and planets are presumably just projected onto the dome somehow? Kind of like this: https://metro.co.uk/wp-content/uploads/2017/02/flat-earth-1.jpg
As for what's beyond the dome or why nobody's ever encountered the edge of it, I honestly couldn't tell you lol.
I used to work with a flat earther and this is the description he gave. He was raised Christian and attended a Christian college, so I guess he was never taught much science.
I don't think flat-earthers are capable of indulging in concepts like other planets. They're entire personalities are completely dedicated to indulging in their silly "theories" and insisting that it's important.
For example, have you ever asked a flat earther what possible incentive could there be for "the government" to lie about the shape of the Earth? The only answer they've ever given me is "control", then they get very smug as if this someone proved something and won't really discuss it any further. I don't think they're capable of imagining anything beyond that.
I can't imagine how the shape of our planet can be used to control us. I mean, if the earth was neither round nor flat, but.... I don't know, toroidal. How would that affect our behavior?
Is non-Euclidean geometry more likely to make the population docile?
And why not use the flat earth as a form of control? Since that vision is much more limited than the traditional one, since there is no space, no gravity, no planets, no stars and no cosmos. Just what you can see and nothing more.
Aren't all of those just fake images the government displays on the dome LCD covering the world inside ice walls? If they were real they would have dropped out of the sky already.
If you're trying to apply reason to the theory, I think you're misunderstanding the theory.
When you dig to the roots of flat earth, it's a "don't trust the secret globalist government feeding you lies" kind of thing (Aka a dog whistle for antisemitism)
"all antisemitic conspiracy theories are deliberately introduced cognitohazards from the illuminati to control the populace" is the best conspiracy theory regarding jewish folk i've ever seen.