The relatively cheap P900 on the market made it so citizens were able to prove that curvature is a myth. A consumer grade camera with a long focal length produced hundreds/thousands of videos of ships sailing "over the horizon", only to pull them back into focus by zooming in furthur. The ships "disappeared" due to perspective, not curvature. With consumer grade cameras, people are taking pictures of structures across 1000s of miles of sea-level, where "curvature" would make it impossible.