I think that's rather well known (but we're not supposed to talk about it). There is no correlation between education funding, and educational outcome.
The money benefits employees, but has no effect on students. So, why do schools exist? To benefit employees? Or students?
(The answer is: to benefit employees.)
Jerry Pournelle (the science fiction writer) did research on predicting which students would do well in college base on their high school.
It was an honest study. The results were so “sensitive” that they gave him a degree, even though no publication dared to print the results. Turns out that some of the most highly touted suburban schools turn out students who are unprepared for college. If you didn’t live in the area and compare the schools, the variance between supposedly equal schools (by cost-per student, race, income of parents, etc.) is astounding.
The top 5% of schools (government, private, parochial) are amazing. The bottom half are appalling, and in the bottom 20%, the parents would be better off paying for an arsonist so the kids would be somewhere else.