>>214678668
They're not necessarily needed down on Earth. Everything people want to make in space is far more economical using material that's already up and away from a gravity well rather than spending fuel dangerously moving it out of heavy gravity. Go mine ice and you get water for drinking, oxygen and hydrogen for fuel. Water is heavy as shit. Go mine metals for ships and stations. Go hollow out asteroids to make way stations because you always need ports to stop at on the way to places.