There really shouldn't ever be billionaires.
I mean really, why the fukk should individuals have more money than they could ever reasonably spend in five lifetimes? Nobody should be able to hoard that much wealth. What the fukk net benefit is there to society at large to have people with more concentrated wealth than some small countries? What does there being billionaires do for the average member of society other than make society inherently unfair and stilted towards them? Literally nothing will ever cause them to lose their money and hoarded wealth and assets. They have to be forced to even give back any of it into the general economy.
Especially because, as is repeatedly shown to us, they have one and only one solution to societies problems and that's to have us plebs work from birth to death for their amusement and to sustain their infrastructure because they fluke'd into a shytload of money so clearly that makes them better people than those of us that just grind it out for a living.