I guess what it would take for a flat earther for evidence would be circumnavigation going from North to due South with no variation and back to North with no government involvement. Or, travel around the Antarctic without government intervention.
“https://reddit.com/r/FlatEarthIsReal/comments/10x6wyu/no_north_south_circumnavigationflat_earth_jeranism/”>View Reddit by Kela-el – View Source