I rented a house once in West Portal where the landlord was paying property taxes on the 1970 value of the home, which was something like $70k. The owner was gifted this house and taxes basis from their parents, who originally bought it. The tax bill came out to just a few thousand dollars as of 2020.

Meanwhile my neighbor at the time bought their house for $3m and was paying something like $35k.

I thought about writing the property taxes in front of each house on the sidewalk with sidewalk chalk to make a point how messed up this tax policy is, but I opted instead to keep the peace and do nothing.

This loophole is used by families in CA as a way to pass assets to their heirs. The worst part is the tax rate also gets passed down, but one generation tops.