Vouchers are less instruments for fostering school choice than incentives for reforms that would obviate choice by rectifying failure. Most serve inner city, poor minority children from homes without fathers present. The public education industry subscribes to this materialist theory. The performance of inner city Catholic schools, which do better with fewer resources, refutes it. So, the powerful predictors of schools' performances are the qualities of the pupils' families.
Schools can only influence the last.
And now there is a movement to abolish homework, partly because it widens social inequalities by disproportionately benefiting children with attentive parents. Most parents are satisfied middle-class consumers of public education. Most teachers' degrees are in education.