That's actually a quite good high-level measure. However, I'd question your measurement: I doubt that Musk, Zuckerberg and Thiel would actually be able to destroy their creations. SpaceX, Tesla, X, Meta, Palantir - they're all large organizations with many stakeholders, and their founders/chairman do not have absolute control over them. The result of any of those individuals attempting to destroy their creations is not guaranteed - on the contrary, I'd expect other stakeholders to quickly intervene to block or pivot any such moves; the organization would survive, and such move would only make the market lose confidence in the one making it.

There's no total ownership in structures as large as this - neither in companies nor in countries. There are other stakeholders, and then the organization has a mind of its own, and they all react to actions of whoever is nominally "running it".

I don't know about the others, but Zuckerberg can absolutely destroy Meta. He owns a special class of shares that have 10x voting power vs. normal shares, so he personally controls about 60% of the votes. If there was any way of Zuckerberg getting ousted by investors, there's no way they would have let the company lose so much money for so long trying to make VR a thing.

Even if Tesla is destroyed by Musk, EVs and self-driving cars are here to stay. If not in USA than in rest of the world.

Musk is clearly doing his best to destroy Tesla.