Yes.
The US\UK model of capitalism has 2 properties that combine to make Billionaires both necessary and sustainable: they are very capital intensive AND they are consumer based societies.
Modern economies need big piles of capital. Somehow you have to get (say) 50bn USD together every time you want a new semiconductor fab facility or Facebook. Someone has to pay for that.
Historically, that money was raised from the middle class: if 20m people have $2500 each in the bank, the bank can pool that and a $50bn pile and lend it to make new businesses.
Those days started to end with consumerism: instead of sitting on a small bank balance, the average American\Brit(\Aussie) is in debt. So that means there were loads of opportunities out there going unfunded. So people who did have piles of cash could now reliably get big returns from lending. They could lend to capital intensive new businesses AND to companies like credit card providers for average Americans to use to fund pure consumption.
That's why you've seen these historically high rates of return on capital for the last 40 years. That's what caused billionaires in the first place AND what sustains their existence. That's why the US\UK have so many, while countries with strong savings cultures (Germany or Japan) have so few. It is also why you "need" billionaires: someone has to fund the average person spending more than they earn and fund new businesses (and to a lesser extent government debt). We could kill all the billionaires tomorrow, spend their cash for the new few months, then suddenly your credit card company would cancel your card as there was no one to fund you buying things and not paying for them, your employer would have to restructure as the interest on it's debt shot up as no one was lending etc.
A billionaire is just someone with a 100m AND 30 years of 8% RoI. They're the natural consequence of under supply of capital and high demand for products.
Wealth inequality is very much a function of individual over-consumption on a mass scale. If you want fewer billionaires, spend less than you earn and put the rest of the money into investments (a bank account or a shares\bond account). Vote for higher taxes and less spending to get the government doing the same thing. Billionaires are flourishing because they basically they hold a monopoly on the capital supply and the rest of us demand ever more capital.