In some ways it's the other way around. Musk (currently holding assets of ~195B) is able to spend billions by selling his ownership in SpaceX (currently valued

In some ways it's the other way around. Musk (currently holding assets of ~195B) is able to spend billions by selling his ownership in SpaceX (currently valued at $180B) and Tesla (currently valued at ~$550B). Musk doesn't need to sell billions for SpaceX to go to Mars or Tesla to make a new car if he never cashes out in the first place. That's why the hard part is (usually, outside of ideological effort) "then why would they bother to keep doing all the work if they don't get anything out of it?". It's also a reason wealth is a hard thing to really track when you want to limit it. Is that corporate jet 1/5th the CEO's because he is 1 of 5 that uses it or is it not part of the CEO's wealth at all? There's not really a clean way to cut this sort of thing that I've seen that doesn't either lop off things that aren't personal wealth by accident or allow squirreling away personal wealth in ways it doesn't get counted. That's the hardest part of this kind of thing IMO.