we already know what happens when assessed values are artificially capped, prop 13 has torpedoed funding for californian schools, among other catastrophic effects.
There are problems with prop 13 (being a bandaid solution to appease the senior/older tax base) but schools in the US are very well funded, when you look at per year/per student in k-12, usually up there with countries like Switzerland and Norway. Its how the money is used that is the problem.