Why would you build on a plot of land when the plot of land itself is already appreciating in value with you doing nothing to it
Building is risky and costly
Having an asset that appreciates on its own regardless of what you do with it is not
Holding costs of land are far from $0 in any major metropolitan area. Sitting on it involves its own form of risk.
Vacant land that's desirable is often held back from development due to zoning or infrastructure issues.
In Texas, at least, the lack of income tax is made up for in property taxes. Just owning that plot with nothing on it is still going to be a sizable liability.