There's also a factor of iterativeness. I think everyone here will appreciate the value of designing something you can do step by step, with value at each step

There's also a factor of iterativeness. I think everyone here will appreciate the value of designing something you can do step by step, with value at each step of the way. You don't have to go zero to 100 immediately. You can course correct. You can revise. You learn from 0-50 to do 51-100 better. Facebook can be built that way. Google too. SpaceX, maybe not so much. It's simply a harder and more expensive and riskier investment to do something that has so much startup cost before you start to get any value or pivotal learnings back.