Landing a rocket on earth is technically a lot easier that making a self-driving car. The former is in a complex but reasonably well understood area of physics

Landing a rocket on earth is technically a lot easier that making a self-driving car. The former is in a complex but reasonably well understood area of physics plus some advance manufacturing. The latter is cutting edge AI sitting in the middle of a legislative/political/ethical quagmire. Ashlee Vance's biography actually explains this really well, how one paper SpaceX looks far more difficult to pull off than Tesla but how in reality it's the opposite.