My primary aim was rhetorical flair as opposed to precision. “Billionaire” is just a lucrative cut-off.
To what extent they have generated wealth is irrelevant to my argument. All billionaires have created wealth to some degree, even no-name heirs. Sure, it’s principled and “fair” if billionaires are taxed at the same rate as everyone else. But there are equities to be weighed in a modern, civilized democracy, and for practical purposes wealth isn’t an infinite sum game either. Musk is the poster child for this; he obtained and spent his fortunes without any extralegal means by and large (though unethically at times). But the propensity for billionaires like Musk to inflict grave harms onto our sociopolitical life is much greater than it is for altruism. At a certain point extreme wealth has to be restricted.
It absolutely is specific to billionaires/the uber-rich, though. Sure, they have the highest nominal tax rates. But the amount of loopholes and writeoffs and deductions made available to them, oftentimes bought by their own wealth, makes many billionaires pay an effective tax rate lower than the middle class.
Wealth attained via speculation does not equate to productive economic output. That’s mostly what I meant. Nothing contradictory about that whatsoever.