The Office for National Statistics says that of the 52% who struggled, three-quarters of parents gave a lack of motivation as the main reason.
So, it wasn't the lack of technology or teaching and learning materials as ever so many expert commentators wanted it to be. And it had little to do with wealth, poverty, race, religion etc that were also hoped to be causes.
No, it was largely down to the motivation, or lack of it, of both parents and pupils. Many parents said that they lacked the skills to enable them to teach, especially those of teenage pupils, and that this demotivated them. And pupils claimed that the work was boring, so nothing new there.
Teachers will know both things to be true and that they are a combination that blights education in the classroom on a daily basis.