It all depends on the quality of schools available to parents though. I can honestly say, that for a lot of the children in the state schools I have worked in, they have maybe had 2 hours a day IF they are lucky of active learning.
Issues such as:
* Cover lessons (sick, absent, or shortage of teachers).
* Behaviour problems (v hard to permanently exclude now). 4 or 5 disruptive students in a class of 35 can totally wreck learning for the whole class.
* Pre-planned lessons (planned by an 'expert' in an academy chain office somewhere - NO focus on individual student needs and teacher forbidden to deviate from the plan).
* A poor national curriculum (designed by idiots with no educational experience, thank you Mr. Gove).
* ONLY teaching what is needed to pass an exam and not pushing students higher (in schools that only teach up to Y11)
I have experienced some or all of those in every UK state school I have ever taught in. I have also seen some phenomenal teaching but teachers are worked to death and do not have the time or the energy to meet the needs of every single child.
There is more to learn than just what is on a curriculum. And there are multiple exam boards. What if your child could perform better, with, say AQA rather than OCR? No choice, in a school.
This is mostly a rant about the state sector. If your children are privately educated, you can pick the school that you think will suit their needs. Most parents don't have the luxury of that choice. IF home schooling is an option for those parents, it could well be better than a very poor, underfunded, academy chain school.