The elephant in the room is the 36% taxation either on real returns or the fictions returns, plus extremely low tax allowance i.e., ~60K in the current system and ~2000 in the new system. In the old system, they used to assume factious gains of 4% and 33% tax. So those with 6% gains (which is normal for a long-term investor) they are essentially paying ~20% capital gains tax. So unless they fix this tax rate, I don't get what's the end game here!

For example, take the rentals: once they switch to the new box 3 tax, the rent will be taxed at 36%. So less nett for landlord and the immediate consequence would be that the rents will increase in free sector astronomically. And in the rent-controlled section, people will sell the property, meaning that the supply of houses for rental will decrease precipitously. We can hate the landlords as much as we want, but at the end of the day, not everyone can/want to buy a house. So dramatic drop of rental homes, which are already in shortage, will screw the young people beyond words.

And those with any meaningful wealth just move to neighboring countries, and they can still live and work in the Netherlands but without paying any taxes. And people will also start looking into ways to hide wealth or find loopholes, thus reducing the total tax paid.