I don't see how this can work in practice. You grant the government infinite power to come in and say that your land could surely be used to build a 50 story luxury apartment building and therefore you now have to pay tax on a $50M imagined value. Even though the land might actually only be worth far less on the open market.
This is basically just a way to arbitrarily take away land from owners without any controls, since nobody can afford to pay taxes on imaginary buildings that don't exist.
I don't see how this can work in practice. You grant the government infinite power to come in and say that your land could surely be used to build a 50 story luxury apartment building and therefore you now have to pay tax on a $50M imagined value. Even though the land might actually only be worth far less on the open market.
This is basically just a way to arbitrarily take away land from owners without any controls, since nobody can afford to pay taxes on imaginary buildings that don't exist.