A property tax isn't a flat tax, as the people who own the highest value assets--and are thereby able to use them to extract the highest rents from other people--are paying higher taxes for that continuing privilege. The reality is that homeowners can feel poor but they are ridiculously richer and more powerful than people at the same income level who are merely renting.
If you want to limit property tax, but you don't have really really strict rent control laws (which California does not: some areas--including, notably, San Francisco--do have some minimal mechanisms, but they pale in comparison to the power of prop 13 for property owners) you end up with an extremely unfair tax system...
...which, though, does favor people with more money, and so this actually furthers the narrative of how the people who moved away from California because they wanted to not have so much tax on their income are now realizing they have a lot of assets and want to capitalize on that in California.
If you want to limit property tax, but you don't have really really strict rent control laws (which California does not: some areas--including, notably, San Francisco--do have some minimal mechanisms, but they pale in comparison to the power of prop 13 for property owners) you end up with an extremely unfair tax system...
...which, though, does favor people with more money, and so this actually furthers the narrative of how the people who moved away from California because they wanted to not have so much tax on their income are now realizing they have a lot of assets and want to capitalize on that in California.