> yet we're still stuck with people who think the earth is flat.
Very few. They are louder online. I have never met one in real life.
Yes, the internet does spread misinformation, but I think its pessimistic to think it outweighs the benefits. A lot of the problems are economic and social at the core too.
but, the earth is flatter than it looks … since, according to GR, spacetime is convex around it gravity well