Your basis seems a little low...maybe 2002 instead?
https://www.cnbc.com/2019/07/01/how...e-bought-10-years-ago-could-be-worth-now.html
Which is why it doesn't surprise me that my buddy's ~$1.5 million (Zillow) house now runs ~$10k/year in property tax, even though it's not in SF or LA.
I looked up median home prices in the Bay Area in 2012 and 2022 in my calculations.
2012 -
https://www.sfgate.com/realestate/article/Bay-Area-home-prices-up-24-6-over-2012-4356658.php - $405K
2022 -
https://www.sfchronicle.com/projects/real-estate/bay-area-home-prices/ - $1.42M
$405K X .0125 = $5,062. After ten years, at 2% increase that is $6,050, property tax after 10 years under Prop13.
$1.42 X .0125% = $17,750, market rate property tax. Difference is $17,750 - $6,052 = $11,700, benefit from having Prop 13 in place.
The article you posted had average not median prices, which are skewed upward by very expensive homes, like including Bill Gates in average net worth calculations. But even then they were in the five hundred thousands for 2012 in the Bay Area.
Using $550K, that comes out to $8,216 in current property taxes, a benefit of ($17,750 - $8,216) = $9,340K from Prop 13. So even using average, not median home price, a home owner would pay less than half of market rate taxes under Prop 13 after 10 years.
Home prices in the U.S in 2002 were actually not much different in 2012, according to a news article from 2012,
https://www.nbcbayarea.com/news/local/real-estate-time-machine-home-prices-at-2002-levels/2070516/ - "Home prices in the United States are eerily similar to where they were about 10 years ago, according to a report published by CoreLogic Inc." So the 2002 calculations would be the same.
TLDR: So short answer, no the median home price numbers I used are correct. You used average instead of median, and even using average prices, there is still a $9,340K annual benefit from Prop 13 for homes bought from 20 to 10 years ago.