The big difference there is SpaceX was able to incrementally build up. Falcon 1, Falcon 9, Falcon heavy, Starship. Each step allowed them to prove that it worked and gain investors and government contracts.
Who in their right mind would invest $10b just to build the manufacturing capability without having a well established product? And if you have a well established product are you still a startup?
Who in their right mind would invest $10b just to build the manufacturing capability without having a well established product? And if you have a well established product are you still a startup?