While I understand what you are saying and agree with it in principle, people who have multigenerational investments in land don't just pick up and move. In our county, property taxes were at 8.5%. I want you to imagine an $85,000 tax bill every year. It was robbery. Of course, all property taxes are robbery in principle.
The damage that Proposition 13 really did is that it made it tolerable to allow Democrats to remain in power.
But then the city I lived in was run by conservative Republicans.
If you are/were living in a city run by liberal Democrats then you should expect your taxes to become ridiculously high.
In most states the mill levy varies from city to city. It is usually included as part of any real estate ad so buyers can decide if they can afford to live in an otherwise inexpensive home in an expensive neighborhood.
In Boulder they tended to tax higher for all of the liberal nonsense that the citizens voted for. But they had a concession for the senior citizens: the seniors could continue to pay taxes at a constant rate, but the city would keep track of the difference between what they paid and what they should have paid. When the seniors passed away a lien would be placed on the property for the difference. If the children could afford it, they could pay off the lien and keep the home, otherwise they might have to sell it in order to pay off the debt.
Of course in California seniors believe that somewhere in the Bible or the US Constitution it states they have a God-given right to pay low property taxes throughout their lives and pass on their house to their children debt-free.
I'm still looking for those passages, but have failed to find them.