You can see things that are 300 miles away if the conditions are right. Which should be impossible on a ball with the curvature and all. You're assuming a lot of things in your questions. Space doesn't exist like you think. Planets aren't rocks flying through an endless space vacuum. You're assuming the size of the sun. You're assuming that light goes forever which it doesn't. Ever heard of the inverse square law of light? You're assuming a lot of things that flat earthers do not claim.

You can see things that are 300 miles away if the conditions are right. Which should be impossible on a ball.