Making space exploration 1000x cheaper basically. Not kidding, that’s roughly the goal I believe. That’s needed to make it possible to send enough stuff and people to Mars to make us a multi planetary species. It’s a completely crazy goal/idea, but that’s actually been the goal of SpaceX from the start. Getting Starship to work seems incredibly difficult and almost impossible, but so did landing a big booster rocket on a drone ship and today they do that so often it’s almost become boring.