Comment by roenxi
The quality of an education isn't proportional to the amount of money spent; learning is remarkably cheap if a school wants to focus on outcomes. There's a bit of give in where the teacher sits on the bumpkin-genius scale (although even then, the range of salaries isn't that wide in the big picture).
Although forcing the funding to go through a collective rather than letting people choose a school and pay on in individual basis would probably deliver a pretty serious blow to the quality.
The school system is downstream broader social issues here. It can be shockingly expensive to deal with the various behavioral problems that disproportionately impact students from lower income communities. Students from stable homes with available and invested parents practically teach themselves.