> 2. You've wiped away the incentive for getting-big mentality which drove some of the billionaires to innovate which advances society to this point. Think - discouraging a future Jobs from making another iPhone-like device.

Am I meant to believe that we wouldn't have iPhone-level innovation if inventors couldn't become billionaires?

This makes no sense. We have so much more innovation than we have billionaires, always have. Ability to become a member of the 0.001% is not a barrier to innovation, not in America, not anywhere, and never has been.

No one serious is claiming there should be zero wealth inequality. Inequality is ineradicable. The claim is that wealth inequality can reach a degree that becomes corrosive to society as a whole and severs the link between innovation and profit, because it becomes more profitable to hoard wealth and collect capital gains and interest than it does to innovate and create things in the real world.

It's entirely possible to preserve (and in fact would actually strengthen) the profit motive if we changed incentives to get rid of the wild capital hoarding we see today.