Looks like they're coining a new legal term "Capital Growth Tax", under which they are going to tax unrealized capital gains. I'm not aware of any other country that taxes them like that (besides wealth/exit taxes), so maybe they're the world's first here!

Some countries have wealth taxes - but they are usually flat or scale with wealth, not the yearly increase in wealth. Note that currently NL does de facto have a wealth tax in Box 3 system - shares are presumed to have a fictional fixed yield of around 5-6% per year on which they charge you income tax, so it works out to about 2% wealth tax.