From there tax basis more or less tracks market value, but it’s possible to protest the assessor to keep it below market value (though it’s time intensive and requires in-person hearings).

To get ahead of any artificial attempts at deflating tax basis, Dallas also maintains a comprehensive public lot value database that assigns a land value for tax purposes based on census tract (initially likely a product of redlining, but now based on average census tract market value) — so, similar to a pure land value tax, even if you’re sitting on an unimproved piece of land, you’ll still be taxed similar to the average home in the neighborhood, which has the effect of setting a tax floor.

Austin is similar, I believe. Most cities have to, as aside from sales tax property tax is their only source of revenue, because any sort of income tax is constitutionally banned.