The trouble with that is that they're all fronting Russia's efforts to control the US government. This is why prosperity isn't exactly in the cards: that's the promise, but all the actions lead directly the other direction in conclusive ways.

Because that's the background, it explains Trump's prominence. He is trusted by Russia in ways a Musk or Thiel can never be, so if we're talking mysterious falls from balconies, it would be Musk, Thiel et al who are more in danger. They have to work with Trump, because Trump is the one Russia trusts, and that's because Russia made him. His wealth has never been real: he's an op from way back.

The Kremlin absolutely will not trust Elon Musk, nor should they. He's more capable, but he is most certainly scheming against them or even looking to supplant/eject Putin and replace him. Thiel is on less drugs and has the sense to stay out of the spotlight, so he will be trying to offer eternal life to Putin or something like that. Whether there's any truth to that is moot: it's whether Putin believes there is.

None of them are safe replacements for Trump, because they all hold power of their own. Trump stays so long as he lives, because he doesn't hold power of his own, and is therefore safe to use as the puppet.