The California situation seems totally bizarre. Where I grew up (D.C. suburbs), the situation is exactly the opposite: https://www.washingtonpost.com/local/education/report-finds-... ("Petrilli said the study found that Arlington and Fairfax counties spent more money to serve students who attended schools with a high percentage of students who are eligible for free and reduced-price meals, a federal indicator of poverty. Other districts did not, he said.").
Similar where I live now in Maryland: https://conduitstreet.mdcounties.org/2016/04/26/chart-shows-.... Baltimore City, among the poorest, spends the second most. Surrounding Baltimore County, which is much wealthier, spends substantially less. Montgomery County, the richest in the state and a suburb of D.C., spends about the same as Prince Georges County, a much lower income county next door.