Almost every problem in the world would be dealt with meaningfully if we outlawed billionaires.
Everytime I look at small problems or big global problems, if you follow the money trail, it all leads to some billionaire who is either working towards increasing their wealth or protecting their wealth from decreasing.
Everything from politics, climate change, workers rights, democratic government, technology, land rights, human rights can all be rendered down to people fighting another group of people who defend the rights of a billionaire to keep their wealth or to expand their control.
If humanity got rid of or outlawed the notion of any one individual owning far too much money than they could ever possibly spend in a lifetime, we could free up so much wealth and energy to do other things like save ourselves from climate change.
I think billionaries are a symptom, not a cause, of the disease.
Some people are born in positions where they already have massive wealth and they grow up with connections to make it larger and larger. So that's what they do.
But the real issue is the system that keeps everyone in debt for life. Many would like to stop working and enjoy their lives instead. They don't need much. Just don't want to work and get by with decent living standard.
That would be one of the ways to deal with excessive wealth .... get rid of excessive inheritance. If you are billionaire .. you get to leave two million dollars per child but nothing more.
Two million dollars to start any life would be more than enough for anyone.
But to inherit multi millions or even billions is a completely unfair advantage to everyone else. Imagine if you were a natural born psychopath or you just have an unnatural shortage of empathy for others and you inherit half a billion dollars ... do you think that person would go on to do good things in the world?
I think the real problem is enforcement. Their children would see it as theft, and so if they said no, we're not giving it up. Then in the end, you would have to send somebody with a gun or violence to "persuade" them to do so. And unless you're some sort of psychopath, which is what most governments are, you are not willing to hurt people, so you can't take it away from them.
In the scenario you describe, the billionaires get to engage in any degree of harm they want, hurt anyone they want, because only a "psychopath" can stop them.
In the scenario you describe, the real problem isn't the billionaire. The real problem is your condescension of people for being willing to enforce a reasonable standard of behavior. The real problem is your declaration that stopping them is an act of psychopathy.
If it only affected yourself, that degree of pacifism would constitute suicidal ideation. But you're judging others similarly affected, and not just yourself. That's not suicidal ideation. You're weaponizing pacifism for the benefit of billionaires. That's... Disgusting.
I think humanity seems to have this need to centralize everything with just a few people. If billionaires are so bad, then people should not use the services that billionaires create and get rich off of and should decentralize, so things like Walmart should not exist and local grocery stores should exist. People should not use things like Amazon in favor of trading more peer to peer, but that's less convenient.
Centralization is not the problem. Centralization is one of the keys to efficiency. Grocery stores are a centralized solution. Decentralization of the food supply would mean we each grow our own food in our back yards. (Even that is centralization... True decentralization, we would forage for food in the wild, rather than growing it in a dedicated place near our homes)
The problem comes not when we centralized, but when the store owner decided to take a share disproportionate to the value he provides. When the efficiency of his operation saves production costs, but those savings never reach back to workers or consumers.
The next problem comes when he acquires enough power in the marketplace that he can dictate terms without worrying about losing market share.
The solution is to dictate back to him a "level of futility." A level at which any future gains are confiscated, so there is no benefit for squeezing workers and consumers any tighter. A confiscatory top-tier tax bracket was the solution to the Robber Barons of the industrial revolution. Abandoning that control has been an unmitigated disaster.