Semi-related, my ideal taxation plan looks like this:

When doing new, big projects, it makes sense to try them out on a small scale, then see how it goes and scale it up later. For an initial set of parameters, i propose the following:

Assume you live in country CNTRY.

• If you own less than the tax-exempt amount, you pay no wealth taxes at all. The tax-exempt amount is $10m.
• If you’re a citizen of country CNTRY, no matter where you live, your total wealth gets calculated, and you have to pay wealth tax on everything above the tax-exempt amount to the country CNTRY. The tax rate is 3% annually. E.g. if you own $25m, the tax-exempt amount is $10m, and the non-exempt amount is $15m, so you pay $450k annually.
• If you’re not a citizen of CNTRY, there is no tax-exempt amount for you and you have to start paying wealth tax on everything you own inside CNTRY. This is to avoid tax-avoidance schemes, like people investing in other countries to avoid paying taxes in their own countries. E.g. a person owning $250m might invest in 25 different countries, where in each of them the tax-exempt amount is $10m, sothat they don’t pay taxes in any of the countries.