Space launch is not like cars or really most other products. Your customer is highly technical and highly informed and they absolutely will not launch on a rocket that doesn't meet certain design criteria and in many cases they will require the ability to review the rocket's actual design blueprints and software (with NDA in place). NASA and the DOD will demand this, full stop.

If SpaceX didn't have someone like Shotwell pretty much running the show there's no chance they'd ever get a customer beyond the low end of the satellite launch market. They'd also have trouble getting the FAA to allow them to fly, and with good reason. A rocket is basically a bomb that explodes in one direction, and many of its failure modes involve it exploding in all directions.

Elon's been great (at least in the past) at assembling teams, getting funding, and motivating people to do really hard shit. (Not sure how he'd fare today with his baggage... his brand has taken a hit.) He also knows enough about engineering to hire competent engineers. Beyond that I see little sign that he's actually good at managing or day to day operation and certainly seems no good at product design. This differs from Jobs who at least had killer intuition there. Jobs would have laughed the cybertruck out of the room.