Then no founder continues building their business once they near having $100M equity. Basically it creates a cap on private business size? Maybe reasonable, m

Then no founder continues building their business once they near having $100M equity. Basically it creates a cap on private business size? Maybe reasonable, maybe not. It is a negative incentive to never try to work more to earn more. Suddenly you lose your serial entrepreneurs. Disincentives matter as much as incentives. In New Zealand, the party suggesting a wealth tax, was going to levy it if you had more than $1 million equity. There is no reason they wouldn't reduce the limit from $100M over time. Politicians want power, why would they want to allow anyone to have significant assets? One fundamental strength of capitalism is that it finds compromises between competing needs - compromises that our politicians can't or won't make.