The BBC website has an autoplay video covering a recent “Flat Earth Society” convention in North Carolina. It certainly seems to have been better attended than it should have been. But the perpetual question about flat-Earthers is: how many of them are actual believer, how many of them are there as a lark, how many of them are outright pretending to believe? Flat Earth is such a patently ludicrous notion that it seems like it would be reasonable to suggest that most people who claim to buy into it really don’t. But then you look at the vast spectrum of stupid that humans glom onto with a passion and… yeah, I suppose there really can be that many people who actually think the Earth is a flat disk.
As with most conspiracy theories, I doubt that most true believing Flat Earthers could be logicked or evidenced out of their belief. And the harder you try, the harder they’ll dig in their heels. It provides them a sense of wonder coupled with a sense of “I’m one of the *special* people because I know *The* *Truth.*” Such a feeling cannot be reliably countered with “No, you’re not.”