[UI confusion led me to think this was a reply in a nyc specific comment chain. It’s still relevant but less perfectly so.]

You land-tax to make sure the most efficient buildings end up using the land. But the construction industry in towns like SF and NYC is mostly constrained by what you can get approved, which comes down to connections and what politician-pleasing giveaways you have to tack on.

And expensive downtown Manhattan land has lots of potential competition, but with transportation infrastructure costs running $2 billion a mile (!!!!!)