I really don't understand why school vouchers aren't more popular. Parents need to have the ability to choose where to send their kids. They have much more agency in private schools where they are the people paying salaries.
I think the best way to fix the education system would be a voucher based system where the vouchers would be X dollars which would cover public and some private schools, but parents would have the option of choosing where to send their kids and if they want to spend more to send to better schools. Make schools compete for students.
There should also be some standard homeschooling kit or some sort of national resources that enabled parents to homeschool more easily.