We're talking past each other a bit I think. I've been trying to convince you that having billionaires is bad and we should have a world where they don't exist. I'm not sure that I have, but now you seem mostly concerned about how we get there.

When I said the money goes to the government, I meant profits past a certain net worth. I concede that this is more complicated for unrealized gains. So here's a tentative solution: if you have unrealized gains that are worth more than the threshold, you're forced to realize the amount you're over at the current market price and your profit gets taxed. This would be the process when we're already in the new system, without billionaires.

If we're talking about the process of getting rid of billionaires: are you a billionaire? No? Do you have enough shares of Apple where you, perhaps with the cooperation of 5 other shareholders, outvote all other shareholders? Or can exercise strong pressure on the board/CEO? No? Then I don't think anyone should be coming for your shares.
But if the answer to one of those questions is yes, all your shares past the threshold are divided among the workers employed by Apple. If you're worried your remaining shares will go down in value in the future, just sell them now. Maybe you're even allowed to sell a certain percentage before your shares are redistributed.

For discussion's sake, my own idea of a decent threshold would be in the tens of millions. Perhaps $80M. It's arbitrary and I'm not particularly committed to that number. But you best believe I'm nowhere near worth that. And neither are 99.9% of people. It would of course be kept in line with inflation.

If we're still talking about the initial asset seizure with the sneakers. If I own 10% of a $1T company, I have a net worth of $100B. I'm not taxed 90% of that, $99_920_000_000 (99.92% in this case) worth of the stock is divided among the employees of that company. If I want, I can sell $80M worth of stock before that, but anything that brings my net worth (excluding my remaining stock) over $80M gets taxed at 100%.
If the stock doesn't appreciate in price and my net worth didn't increase in some other way, I'm not getting taxed again next year on my stock. This "getting taxed to 0" concept is a misdirection to try to confuse workers about progressive taxes. You get taxed until you're at the threshold (which is still much more than most people will ever have). You're not ending up poor, or even middle class.

I agree with your last paragraph. But both the corruptors and the corrupted have a strong incentive to keep the status quo. They always will, in capitalism.
And besides that, being extremely wealthy doesn't just give you political power through bribes. You probably have powerful friends, many of them probably owe you a favor or two. If you control a big company, you can even push governments around out in the open: if your state doesn't write/keep laws that make me more money, I'm going to close up shop in your state and leave 10% of your workforce unemployed over night. Unelected people simply shouldn't have that much power.