We should in some way couple the amount of money retirees receive (don't know how it is calculated in the US, here it is dependent of how much you earned in life and how many years you were working, with a minimum and maximum value) to the maximum amount a single person can directly and indirectly own. If your investments get over the limit, you can only spend, but not earn more money - in some cases this might result in you having to sell off something you own and donating what you get for it (and you can't use your investments as collaterals for a credit line when over) until you are back below the max.

No human being can own more than the average insurance value of a human life. Raise the average value of a human life if you want more money. That's my solution.

Yes, that's why I keep saying America's problem is the boomer class. By value of assets it's 8 times bigger than even the billionaire class. And that's just boomers, it gets worse when you include the older ones (silent or greatest or whatever).