One idea I really want to see percolate into the Zeitgeist? A national wealth cap. We can have a world without billionaires. Though, they did kill the last guy who tried it.

My justification for it is simple. We do not allow people own nuclear weapons. We don't care how intelligent or moral a person is. We don't make them take a bunch of classes or earn a difficult-to-obtain license. We simply accept that no individual, however sane and moral, should have access to that level of power. It is simply too great a risk. Yet people like Bezos or Musk have so much wealth that they can, all on their own, cause a level of damage comparable to a nuclear weapon. Hell, those two have built actual privately owned machines with the explosive capability of modest nuclear devices. There is such a thing as a strategically dangerous level of wealth, where the wealth of a single individual makes them a national security risk. No one should have level wealth and power, period. The only way to obtain such power should be through democratic elections.

I would set such a cap at 1000x the median household income. That way it automatically grows with inflation, and it's a simple enough rule that it can be explained to anyone. Someone with an 8th grade education can understand what such a cap means. 1000x is not only a nice round number, but it also represents a nice break between wealth earned through working and wealth earned through labor arbitrage and hoarding. 1000x the median household income is about $80 million today. If a neurosurgeon or other members of our highest paid, most educationally-demanding fields were to work their entire life, live like a pauper, and invest every penny? They would still struggle to reach that 1000x cap. The only way to reach that level of wealth is to be born rich, to make your business arbitraging the labor of others, or to be a CEO of some sort. It's the kind of wealth that even the most frugal and well paid of workers would struggle to ever get near.

1000x the median household income. Everything beyond that is taxed at 100%. The ultra wealthy can either pay the tax, spend all their extra dollars, or get really into philanthropy. (Oh, and if you donate funds to a charity that you or your heirs control, that charity's assets counts towards the 1000x cap.) It really doesn't matter what they do with the extra money. The goal is to prevent the accumulation of strategically dangerous fortunes.

Tax the billionaires out of existence. And if they flee the country? So be it. Don't let the door hit you on your way out. And while they can leave, their wealth is largely in ownership of businesses that can't so easily be moved. The Waltons can leave the country if they want, but they can't take Walmart with them.