Destroying a child's social life in the name of bringing them up to a standard of state defined literacy is worse than the illiteracy. Consider Rousseau's, "Emile; or On Education." I was called a, "failing student" in school because I was sneaking off to the library to read Kant and Hegel as a teenager. I once got suspended for asking my math teacher about Godel's Completeness Theorems because it was, "smart alec'y"
Please apply the golden rule to your assertions and think of unintended consequences.
People who flunk 3rd grade reading do not sneak off to read Kant or Gödel.
I don’t think people who leave school being unable to read are likely to end up with a very good life either.