With most problems in society there is a huge stumbling block that people aren't actually interested in resolving because it conflicts with their other interests.
For example: homelessness. The number one cause of and solution to homelessness is... housing. Housing is too expensive. Housing needs to be cheaper. But too many people have a vested financial interest in maintaining and growing high prices.
Interestingly, high property prices are a big contributing factor here too. Schools are funded by a mix of Federal, state and local taxes and a big part of local taxes come from property taxes. So the wealthier areas get better-funded schools. It's economic segregation in the same vein as redlining.
California in particular has created a massive funding hole through Prop 13, which is essentially a massive tax break for the state's wealthiest residents.
I would add another dimension to this: how gifted? 99th percentile students will largely be fine. There are scholarships and progrrams to find and nurture these people. You start to see more disparities when you look at the 90-98th percentiles. If you're from an affluent background, you're going to be fine. If you're from a poorer background, it's way more likely that things go wrong for you. Your quality of school matters. You may catch a criminal charge of some kind, which can entirely derail your life.
While all this is going on there are significant and organized efforts to dismantle the public education system (ie "school choice" or "vouchers"), which are nothing more than a wealth transfer from the government to the providers of private education at the expense of everybody else.