Herds
Improve how much parents talk to preschool children.
Improve how much informal maths and general knowledge they teach to their preschool children.
Teach parents to rephrase rather than correct children's speech, and to use complex vocabulary with their children and each other.
Help those parents to help their children with their homework, and to have a "learning friendly" household where books are in abundant supply, whether from the library or owned by the household. Including for adults.
Continue to help parents to teach informal maths, current affairs, general knowledge etc. to their children (and to improve their own skills). Improve society's attitude in general to high level learning and in particular to learning of maths (the biggest difficulty with the "I was never any good at it" brigade), but also society's attitudes to experts, and to accurate up to date knowledge about current affairs (look at how many people watch news versus entertainment).
Help schools to identify children early who have potential (but of course children from struggling and less-well-educated families will already be short of their potential on entering school).
Give those children (and only those children, because parents who are not struggling will be able to practice with their own children or pay a tutor) access to additional tuition, and time to practice when they are not being expected to help at home and/or take part in family activities.
Do you really think all those things are going to happen?