It is a disturbing disruptor meme set off by people with nefarious intentions to play on most people's lack of basic physics.
I suddenly started getting dozens of these mindless videos on Youtube some months ago.
There is one very simple proof against this stupidity - just before a lunar eclipse, we can see the shadow made by the curvature of the Earth. QED
The ancient Greeks wrote about this too - they couldn't explain it physically but they also could not argue against the geometry of it.
That's just the dome over the flat earth casting that shadow! On the moon....that is attached to the dome....uhhh...hmmmm.