I would also say that the majority of “flat earthers” are just trolling, either because they what to get youtube views in their videos or just for fun.
“Conspiracy theories” are a good business, all you have to do is invent a crazy theory, blame the government or big corporations for hiding the truth, and make high quality and professional videos.
My best guess is that the authors of these conspiracy theories are people who don’t really believe in the stuff that they promote, but in any case I personally enjoy these theories, videos are entreating, and I always end up learning something.