Just because an observation or measurement agrees with your model it doesn't PROVE your model.
Your model has to account for ALL of the observations and make predictions that can be measured.
A large body of agreement with your model supports that model but it is NEVER proven. It can ALWAYS be wrong.
But a single failure of your model unequivocally disproves that model.
The Flat Earth model cannot account for why we NEVER see the bottom portion of a city at 60+ miles even when the top half is clearly visible. Perspective does NOT squish only the bottom half of something when the top and bottom are at equal distances from our eye or camera lens and Perspective does not VARY over time as we see clearly evidence in the case of longer distance city views.
The Spherical model APPEARS to be wrong until you account for refraction and use the proper mathematics.
Which I show repeatedly:
Chicago skyline 'looming' from MI - explained
Toronto CN Tower from Olcott, NY - explained
And there is a long list of Things Flat Earth Model cannot account for.