> In my part of the country there are places where this situation has persisted for fifty years, as the auction value of the property is only in the hundreds of dollars per acre

At 2021 market valuations, not lower public assessments?

> Even in higher property value areas I would be surprised to see a tax delinquency action taken after just a few years. The administrative cost is substantial

In some areas owner only has a few years then legal department will process tax sale within few months. It's true that in many areas property tax less than 1% of true market value. Prior to 1930s when no state or local government was collecting sales tax it used to be closer 3%.