Except for all the times that the earth appears round. In those cases FET must devise their own imaginative optical effects (perspective causes the sun to appear to dip below the horizon? )
The sunset does not suggest a Round Earth. When the sun sets the sun is disappearing into the horizon. This is what is observed.
The Round Earth interpretation of the event is that the sun has dipped
below the horizon. It is assumed that the sun is down behind/below the horizon despite no one observing this. The RE'er merely assumes. No one actually sees the sun
below the horizon.
The Flat Earth interpretation of the event is that the sun has disappeared
into the horizon. This is exactly what has been observed. No other assumption is made about the occurrence beyond what was empirically observed - the sun disappearing
into the horizon.
The RE interpretation involves making several unverified assumptions about what happens to the sun. The FE interpretation only relies only on what one can see for his or her own self.
Further FE explanations which involve perspective are an explanation of the event on a technical level. We are answering the question of "
How does the sun disappear into the horizon?". When a flock of birds passes overhead the flock will eventually disappear into the horizon, just as the sun does. When a plane passes overhead it will eventually disappear into the horizon just as the sun does. There is a precedence for bodies passing by overhead and disappearing into the horizon.
Never do we invoke something which has not been tested or observed. While the RE'er are content with assuming the unobserved and untested (the sun below the horizon), the FE'er uses known occurrences to describe events. No one can doubt that planes disappear into the horizon. No one doubts that flocks of birds disappear into the horizon. We are using that same explanation for why the sun does it.
Perspective.