Elon Musk emphasizes that the complexity of developing a reusable orbital rocket is incredibly high. That's why "many smart people have tried it before, and no one has succeeded… most have kinda just been given up halfway through." “We live on a planet where the gravity is actually very strong... That means that you have to have ‘A pluses’ across the board, incredibly efficient engines, incredibly efficient structure, you do need scale, that’s why Starship is so gigantic... But if full and rapid reusability can be achieved, it reduces the cost of access to orbit by a factor of 100 or more... The difference between humanity being a multiplanet species or a single-planet species… It’s really that big of a deal.” Video: @SpaceX