My point was rather that props through 13 isn't what's driving the cost of housing up in California. In fact it does the opposite.
If Prop 13 were removed, taxes for new home buyers would go down, enabling even higher costs.
Vacant lots are taxed based on their purchase price, so there's no real reason to develop them when the land value keeps on rising while the taxes don't. Commercial zoned buildings aren't affected by prop 13, which leads to more revenue for the cities, hence them preferring commercial development to housing.
All that prop 13 does is favor people who bought real estate decades ago, at the detriment of everyone else.
You can always argue that the proportion should be even higher, but the proportion of income is certainly not lower
For example, one loophole during the ZIRP era was that one could get a very low interest rate loan (<1% APR, so effectively lower than inflation) against appreciated securities and use that money tax free. If the wealthy person passes away and gives the appreciated securities to their heirs, their heirs have a step-up cost basis which is the market value at the time of transfer, so no taxes are ever paid on the appreciation of the stock. The heirs could then turn around and settle the loan, tax free, as their cost basis matches the market value.
https://abcnews.go.com/blogs/business/2012/01/warren-buffett...
This is an anecdote but there's no reason to expect that this doesn't apply to his classmates.
So, yes; given all the rebates and loopholes and shenanigans that the rich and mega-rich can use, the proportion of income is lower.
Also, a big shift in overall revenue from property tax to income tax. This is less stable source and tends to benefit the investor class over W2 earners.