Billionaires in Europe "evade" taxes just like every other billionaire. Most of their wealth is assets, which is why their tax rates don't seem right if you don't understand how economics works.
I think what limits its effectiveness is mostly that it's only the NL doing it. If it was EU wide, or even US-wide, the world would change a lot.
Even if it's not perfect now, I see that it is good that this tax exists for two reasons:
At least it's not taxing wages or consumption, which affect everyone but billionaires.
It serves as a model for going in that direction, so neolibs can't easily say there is no way to tax assets, or that taxing assets would crash the economy.
The property tax rate where I'm at is 1.7%, and the appraisal districts WAY undervalue properties. A house will sell for 5 million in the city where I work, and their value on the tax roll is $300,000.