Property taxes pay for the schools that already exist. It's hard for a district to 'save up' because, well California, and 'surplus' money should be returned to the taxpayer. If developers don't cover the cost a district usually issues a bond but that's hard because, well, California, and direct democracy rarely votes to raise property tax mil rates whatever it would cost to cover the bond. And doesn't California basically freeze assessment values? Because why should the people who already live there pay for services for newcomers? It's all very hostile and backward.
A state shouldn't need a per-value increase in taxes to cover anything that scales with the number of residents, which would include schools; the additional revenue from the new residents should cover that. (Unless they've utterly failed at economies of scale, but that should not need repeated fixes.) The cost of accommodating growth for new capacity should be factored into the ongoing existing costs. The people already there aren't paying for it; the new people in the new development are.
The hostility is built up of years of expecting each new increase to be the last, and yet continuing to receive urgent demands for more, all with the plaintive "for our schools and our children" exhortations that try to suggest only an absolute monster would dare to say "enough".
Where does it say that property taxes pay for schools that already exist? I have never seen that mentioned on any of my $22K/year property tax documents.