Everything I've read about the man makes me think if you gave him $100b he would invest all $100b in doing some awesome project which would only be successful through the superhuman efforts of himself and his team, but wouldn't require a command economy otherwise. Vertical integration inside, yes.
Tesla started as a supercar company and slowly migrated to what it is today. Electric tech was actually old by the time Elon started, with GM already having built the EV1 program. This was all proven technology waiting for the right group to monetize. It also helps that lithium ion pricing had fallen significantly. The EV1's biggest fault was its old school lead-acid batteries which couldn't deliver the range and power li-ion could. In hindsight, li-ion and electric cars are a no brainer. That combination with, lets not forget, Tesla's and its buyers vast government subsidies turned out to be workable.
SpaceX for all its wonders, exists only because of the COTS program generously funded by the US taxpayer. Its been a long slog to its current levels and still has a way to go, but it has customers and accomplishments to show for itself and builds off rocket technologies that are decades old. Both of Elon's businesses are more refinements of existing technology than pie-in-the-sky daydreaming.
That's very different than giving speeches and interviews about living forever, having a 2001 style AI in your home, and airports run by robots. Musk is still in his peak. I guess we'll see how he turns out, but he's not comparable to Page yet.
Elon Musk doesn't want to rule the Earth.
He wants to rule Mars.
That doesn't really speak to him being a closet authoritarian or anything, though.
I think you make some insightful points about the "weird pattern", but I don't think Gates is a good counter example. He, his wife, and his foundations seem as top-down/central-planning as anyone else, he just isn't as outspoken about it.
Pie in the sky rich guy stuff like immortality (Page, Kurzweil) and central-planning stuff like robot run cities, AI controlled airports, etc are just mindless futurism that either will never happen or will be too impractical or unethical to ever properly attempt. Heck, Page can't even deliver a thermostat that doesn't regularly fuck up in spectacular ways. He wants this cowboy engineering to run cities and fly planes? Meanwhile, Google has competely missed the boat on some real futurist stuff that is actually panning out like VR or private spaceflight.
The only person I can think of who didn't fall into this bizarre pattern is Gates, who just funds a foundation that hands out grants to various organizations, mostly non-profit and NGO, who might get things done. I think this is by far the wiser approach and the one that has the potential for the most change.
Live long enough to see yourself become the villain seems to be in effect here. Most super successful people don't have a second act. They peak and either disappear or just become weirdos who have spent too much time around yes men and in echo chambers.