Has nothing to do with “uprooting families”. Average American families are not the ones grossly overestimating the values of their property. It’s people like Trump who use overestimated values on their properties in order to hide money and grift people into paying him more than properties are actually worth. And then readjusting to actual values, or lower, in order to dodge taxes.

Edit: my reply was not an endorsement of OP’s property assessment plan. I was only speaking to our frustration with the rich who hoard wealth in the form of land and use overinflated valuations of their property to increase their wealth at the expense of everyone else. And even though OP’s idea is flawed there is merit in the idea of altering the way property value is determined.