Who believes in the Flat Earth theory? In a sense, the Earth is both flat and round. On the surface of any sphere, there are flat (at least reasonably speaking) areas. If you're standing on the Earth, you will literally always be, technically, standing on a flat surface. Or on the very curve of it, which seems counterintuitive...
But I also suspect that, holographically, or in another dimension, what appears to us as round could literally have four corners and be flat.
Though I do give credence to our reality, where the Earth is a sphere, being just as valid.
So I say the Earth is round. And it is flat.