Someone who has all their wealth tied up employing thousands of people and making the world a better place is a lot different than an anonymous billionaire who just lives off their savings and does nothing for society.
Whenever this topic rears its head people always assume the latter and try to convince others to do the same.
No billionaire has all their wealth tied up like that. None. Zero. Their wealth managers would have kittens if they did, because from a wealth management perspective, it's inefficient and too risky. Above a certain level of wealth, you're going to "take money off the table" so that you can do important things like guaranteeing your comfortable future and paying your wealth managers.
But even that's conceding too much to your fantasy. The gauzy notion that a billionaire owning shares in something means they're "making the world a better place" is sus in all sorts of ways.
One, a lot of shares in things are making the world worse. The fossil fuel industry alone is worth trillions of dollars, and they're vigorously exacerbating an existential threat to humanity. There are trillions more tied up in finance, most of which is not serving anybody, but instead is parasitic on actual productive work. And don't even get me started on private equity's vigorous (and profitable) destruction of value.
Two, another huge chunk of richie-rich money is from rentier activities. Look at all the shitty landlords out there, for example. Are they making the world better? No, not at all. They're going to buy a thing that people need and squeeze those people for all they can get, generally doing the minimum (or well less) in terms of maintenance.
And three, the productive stuff would still happen in a world where we didn't have billionaires. The magic power of the market would still be there to organize flows of value. Indeed, I'd be glad to argue that it would work better. Billionaires face very little in the way of market discipline. Look, for example, at Elon Musk and Twitter. Even he admits he burned $24 billion so far. Has that slowed him down? Nope. He's still stepping on rake after rake. While his car company also isn't doing so great, having lost $500 billion or so in value.
