Interesting. That's very much in line with what my experiments showed: just on a computer model of incredibly primitive 'economics', you can use an incredibly tiny wealth tax to redistributive effect. I think you can even ditch a lot of sales, income tax etc. if you're prepared to do a wealth tax. It seems to be very effective but this is the first I've heard of it actually being done anywhere.
It started of as a 30% capital gains tax, but at some point the government was like: "Math is hard, let's pretend 4% return on capital." and we effectively ended up with a 1.2% wealth tax.
In the last few years they realized that wealthier people have a higher return on capital and the effective wealth tax is more progressive with an effective wealth tax of ~1.6% at the highest bracket.
In Germany we also get heavily taxed although I don't think it's that drastic: 19% consumption tax, 25% + 5.5% on capital gains, a marginal tax rate that linearly increases up to 42% for high-earners [2].
[1]: https://en.wikipedia.org/wiki/List_of_countries_by_income_eq...
My impression is that marginal taxation here is massive, since we have a sales tax of 25% (consumption tax, effectively), high taxes on luxury goods (cars especially), wealth tax of 0.85% of net worth every year and capital gains tax of 30% with no exemption for long-term holdings. The marginal tax rate on income is 46% IIRC, but your employer has already paid 14% of your salary in employment tax before you're paid. On top of this is property taxes, fees to local government, annual car tax etc.
If you make a complete assessment of the taxes a high-earning, high-spending person pays, it can easily surpass 70% of all income.