Nobody earns a billion dollars; the only way to get that kind of money is to pay a whole lot of people significantly less than the economic value of their labor. The internet economy has just made it easier to abstract away ethical problems such that you don't recognize them as hugely problematic when you're making them.

With the current system, we're reliant on the whims of a couple of billionaires. Some are relatively benevolent, but far more are on the level of the Kochs, Larry Ellison or the Sacklers. Business schools have taught the "fiduciary duty" doctrine for a long time, which is basically "maximize profit above all else, or we'll find someone else who will".