Earlier quoted context omitted.
There's not much the education system can do here. When you look into educational research its grim - its really really hard to move the needle even a few % on outcomes in a school system, even with large grants and volunteers and special projects. Kids on the bottom half of the bell curve, especially without parental support, are always going to struggle at school.
When there's no incentive for the teachers and schools to get kids to grade level, they aren't. I've proposed before having a bonus to the teacher for every student that reaches grade level at the end of the year.
I'd propose to spin that and base it on deltas. Taking a student that was already achieving expectations and is still doing so earns $X. Taking a student that was not meeting expectations and now is is worth 4*$X or something like that.
It should be worth more to take underachieving students and get them up to expectations than it is to maintain students at an achieving level.