> No, it's not good. It leads to nothing but urban decay.

This is subjective and loaded. I don't see any concrete point you are making.

>Except that they don't even decrease. If your population is growing, so is your rent. And it doesn't matter how much you build (for large enough cities).

They did temporarily in Austin - 19% after accounting for inflation.

Overall, making a city like NYC is preferred for any country. Even if the prices are really high, it reflects the economic activity of that city. Why would a house cost ~$800k if the person living there won't make multiples of it with their wages?