If round earth theory were proven without a shadow of a doubt, this site wouldn't exist.
You're wrong because it is proven, and this site still exists.
Prove it!
You can calculate the curvature of the Earth based on viewing a sunset laying down, then getting up and seeing how long it takes the Sun to set the second time.
Oh, and the Sun sets.
The Earth clearly rotates, evidenced by that fact that a time exposure shot of the celestial poles makes a circular pattern.
We've seen it from space.
Eratosthenes proved the Earth was round before 200 BC.
Gravity tends to pull mass towards a center, which would make the Earth a spheroid.
The Coriolis effect proves rotation.
Foucault's pendulum proves the Earth rotates.
GPS proves the existence of satellites.
We've been on the spherical moon.
I'll post more if need be.