I think the world is round because I've seen pictures, and seen ships sailing over the horizon. The real question is why do we think that in ancient times people thought the world was flat when all we've seen to support that is a few allegorical drawings. There's just as much ancient art of what looks like space suits and airplanes. When you look up "ancient space carving" on google the first link is to a modern carving on a cathedral in Spain, and Snopes "debunking". You need to dig just to find anything interesting, despite  countless hours of ancient alien shows, and many books on the subject having been published. The MSM pushes revisionism and whatever NWO narrative suits the elites.