True, but putting a tax on net worth above, say, a million wouldn't affect most of the population - those who are in the most need of the ability to build up s

True, but putting a tax on net worth above, say, a million wouldn't affect most of the population - those who are in the most need of the ability to build up savings would still be able to do so. The key would be picking the point at which net worth is past the "financially independent" stage. Sort of like the thought behind the proof of stake system in Cardano - once a node gets past a certain threshold, the gains flatten out. This means that you wont have just a few nodes dominate the whole network, as once they reach a certain size it becomes more profitable for people to switch to a smaller node which encourages a more even distribution of power. If we implement a similar mechanism, sure maybe we won't have as many people becoming billionaires, but we could have a lot more people that aren't on the financial edge and are thus able to contribute more effectively. Sort of a damping effect for the power law. Individually you may not be able to accrue as much in terms of assets, but everyone in society benefits from having more people capable of contributing to research and development - I think that's largely why we have seen such rapid scientific advancement in the past century compared to the past two millennia.