One of the tactics of communists is to destabilize a country by ripping out all the foundations of the society. History, morality, traditions all must be marginialized and eliminated as much as possible.
Here comes flat earth, to contribute to that. They love to come up with scientific-sounding explanations why the earth is a flat disk, and ignore basic physics. They toss around a lot of complex sounding explanations while ignoring observable facts and invent their own science. It's all done in an effort to destabilize the country, just like all the sexual madness that's being pushed.
For those of a mind to, one should analyze this "FE" phenomenon from a "meta-perspective", outside of the issue of the shape of the Earth itself.
That is, consider those advocating the "wrong side". Certainly some are paid shills, so we can discount some portion, but there is a remainder. The rest are honest people, who we must conclude genuinely believe what they're saying.
One thing about them is that they cannot settle the issue for themselves. In fact, they don't even try. I've never heard any of them say, "Here's what I thought up as a test anyone can do. I did it and these are the results. I invite others to replicate the experiment and report those results, as is the practice in science." This reasoning process is totally alien to them.
I believe that the Dark Occultists, probably via their minions in Intelligence, studied the way the human mind works... and They found a flaw. Of course, this is precisely the way computers and other technical systems are hacked. A few years ago, They launched an exploit based on that flaw and here we are.
Again, science demands an accounting of all the evidence. As regards FE, that evidence includes the fact that numerous people sincerely believe something preposterous.