But point me at any given billionaire and I can provide more context-specific examples, sure.
The default framework is one of private property. If you make it, it's yours, and (modulo taxation), nobody has the right to take it from you. In that framework, it's not a bug that, if someone makes a billion dollars, they can accumulate a billion dollars.
So, do you reject that framework? If so, on what authority? Given that it's the default framework, "I reject it" doesn't cut it. "I think it's immoral" is slightly better, but you need to demonstrate that someone accumulating that much money is more immoral than taking it from them would be.
Or are you claiming that it's immoral for any one person to receive that much money? In a free economy, if others voluntarily exchange that much money for what the person supplies, why is it immoral? What is your moral authority for claiming that voluntary transactions are morally wrong, just because too many of them go to one person?
Any system that allows more wealth than is necessary to accumulate into one pair of hands while another pair hasn’t enough food is inherently immoral.
Also you’ve never, not once, been operating within a free economy… the only people I’ve met in life who have witnessed such an economy have gone to extreme lengths to escape it. Or they’ve died.
That framework is the default for the legal understanding of what is right and wrong. If you want us to change it, the burden of proof is on you. Bare assertions of "that's immoral" aren't going to be enough. You need to make a much more robust case than that, one that's not just soundbites. (At least here. Most people here can think at deeper level than soundbites.)
Yes, under what you’ve accepted as the default it’s legally acceptable to accumulate all the money and avoid any taxation while doing so. Thank you for summarizing and explaining to yourself and others precisely the perverse systemic bug I described earlier.