you're neglecting the important asymmetry. If we fail to tax a rich person, it doesn't actively hurt someone, it may passively prevent some people (who would have wanted to move in) from having an easier time with certain life-paths. If you eject a middle class person from their home, you are actively forcing them to find a new life-path. Suppose that lower-middle class person is a mobility-challenged elderly person on a fixed income that is already being eaten away by inflation. Yes, sure, they get to sell their house at a high mark to market, but they have to suffer the hassle of finding a new place, which at best is equivalent quality minus income tax on LTCG, on an eroding deadline. That is a really shitty situation to be in.

> this wouldn't happen very often

Then, I suppose we would have no reason for the term "gentrification", if it's that damn rare.