In California, it's capped at a knowable amount when you buy the home and pegged at the sale price. You know what it is and what it always will be when the transaction happens. The people whom have owned a house now worth a million for 30 years probably pay a few grand a year and always have. Dry taxing the technical value of their assets today would destroy millions of families. The point is that dry taxation is generally pretty stupid.
I wouldn’t call it stupid, but it is a policy choice. On the other side, why should Grandma pay 5% of the property taxes as the new couple next door while receiving the same access to public services, while also pushing another family to live farther away?
1. The tax is not pegged at the sale price. What prop 13 actually does is limit the amount of appreciation the state can recognize for tax purposes.
2. There are lots of states/cities in the US that do not cap the appreciation of your house for tax purposes, and I don’t think it destroys millions of families. In fact the California cap is generally seen as a terrible policy because it distorts the housing market