The ball Earth is just a mathematical construct, no physical truth of it.

Original ball Earth is a contrived size. It is just 360 degrees times 60 minutes per degree, 21600 units, nautical miles. Then 21600 X 1.15078 miles = 24856.85 circumference, math made the ball Earth

The supposed diameter of the Sun is just how many seconds there are in a day, 86400, the supposed diameter of the Moon is just how many seconds there are in a day, 86400, divided by 40, 2160

What was even worse they tried to put a flat map on the globe and had to distort everything.
The depicted size of the landmasses on the ball Earth Globes are not accurate, people just assume it is.

On the ball Earth miles are longer at the equator miles are shorter and shorter going north and south, results in a distorted land presentation

There being no observable Earth physical curvature rules out concave convex or a ball, has to be something else