This is fairly simple arithmetic. Suppose we attribute the cost of a single family home (one housing unit) entirely to land, and then the cost of land doubles. Obviously the cost of the single family home doubles.

Now suppose construction is cheap and zoning doesn't prohibit this. For 10% of the cost of the land, we could build a condo tower on that same piece of land. Ten stories, 100 housing units. The cost of a unit just went by down by a factor of ~100. The price of the land doubling is dwarfed by the increase in the number of permissible units per plot of land.

> Pretty much every argument you made can be easily refuted by looking at any other jurisdiction that has completely different zoning laws and completely different construction prices and yet prices for real estate are skyrocketing the same, regardless of use.

The places with less restrictive zoning objectively do have lower housing costs, and even most of the places with "less restrictive zoning" still have non-trivial zoning restrictions. For example, name the major US city that isn't accompanied by a significant land area zoned exclusively for single family homes.