If I measured by the standards I have for myself, then I would agree he overpromises and underdelivers.
Compared to the marketing bluster I see from the old aerospace companies and greenwashing from older car companies, however, he’s a spectacular breath of fresh air with his honesty, openness, and willingness to say things have a less than 100% chance of success.
And I say that despite agreeing with you about Hyperloop and TBC.