There are plenty of cases where teachers care more about the success of a child than parents.
And this whole post is full of hypothetical idealism. Go to the library and study the subject with the kid?

Again, yall seem to keep thinking in terms of parents with resources and means.
Our schools do the basics in teaching us how to read, write, science, history, econ, foreign languages, they can do the basics in teaching financial literacy. Like everything else, parents can then go above and beyond by really exposing their kids to the subject or challenging them to learn more, but the basics, that's what your tax dollars are for. Nothing about that means putting your child in someone else's hands.
I deliberately used the word "unlikely" to illustrate my understanding there are some cases where the teachers care more about the students than their own parents do. One of my oldest friends falls into this very category. I know it is not always the case the parent will care more, but many times, it is.
Regarding the "hypothetical idealism", I'm speaking as a child of a mother who had me at 20, was from the projects, had only a HS diploma and never had a lot of money when she worked but she somehow made things work. We were not in any bracket of the middle class. We had WIC, section 8, food stamps and whatever other assistance she had to use to take care of my sibling and I once she and my father split. She was still working to take care of us. By all intents and purposes, I was raised in the hood for most years of my childhood.
That being said, my mother would take it upon herself to go to the other side of town to teacher resource stores and buy teacher books and workbooks for me on a variety of subjects. She only stopped doing this once I got to high school. This was back in the late 80s/early 90s. She KEPT me in those books, would sit down and complete them with me and always had more waiting when I was done. Always asking me questions, always making me read something new or had me practicing my writing...just always something (sigh). At my school, she STAYED in my teacher's faces about me and my grades, starting in preschool up thru high school (what I thought was scary and embarrassing then I can see now was a true indication she really cared about me). If I got bad reports for conduct, the first thing she would tell them to do is give me something more challenging to do. That was her contribution to my education. It was exhausting for me, and now that I'm a mother, I can see it was probably extremely exhausting for her because she was doing it all alone; this was my single mother doing all this stuff on her own because it was important to her. Because of all this effort, I was always in classes with higher grades or in TAG classes, all thru high school.
By her own admission, my mother would tell you she is not very learned academically. There are things about her even now she shows embarassment about regarding her skills as a 59yo. That being said, she will also tell you she did what she could for me with what she already had/knew and she would seek out those who could teach me the stuff she could not. This could be in the form of a teacher and a tutor, getting me a new book to study or whatever she could obtain with whatever she had. She was willing to sit down with me and try to learn the stuff as well.
I'm saying this all to show I'm not trying to speak from a place of "hypothetical idealism". I'm speaking from experience. I have a mother who, for a while, looked at herself as my educator first, and the school was the secondary. She had had bad experiences with school herself as a child/teen and had resolved to be more involved in her own children's education. She also had a mother who cared more about her reaching a certain age without a baby than a diploma. Lol, it is quite laughable to suggest we were ever people "of means".
As I said before, schools have a responsibility to educate the children. Still, my perspective is on this topic from having the kind of mother I have. My suggestions earlier were me taking a page from her book. With what I saw her do, to me, it is not unrealistic to suggest someone go check out a book with their kid and learn together. Library cards are free and a library offers a place to start. Regarding the subject of financial literacy, I have no doubt if my mother, young as she was, would have seen the value in being adept in handling finances in more sophisticated ways outside of using credit cards and layaway, she would have done something to ensure my sibling and I had been educated in that as well.