"It's a systemic problem, so it's important to say there's not just one thing at fault and no one person to blame. But the solutions lie in getting all the parts of the sector to work together."
Chronic absenteeism was one factor - in 2019, only 57 per cent of students were classified as "regular" attendees.
Institutional racism was another, including teachers having lower expectations for Māori and Pasifika students.
The piecemeal and underfunded intervention system for dyslexic children and struggling students was failing many.
Hood said the curriculum itself had contributed to the problem, with its lack of content.
At each level, the curriculum sets high-level objectives that schools are required to teach.
However, it is left to schools to determine specific content, for example, which texts students study for NCEA English.
"On one level that might enable young people to gain the credits, which means they achieve NCEA and that's a good thing.
"But if you look at education more broadly, it's ultimately doing them a disservice because they're not having the opportunity to develop those higher-level thinking, critical skills, develop those higher-order literacy skills, which we know are so important."
Patchy teacher training and professional development also came in for criticism.
"We do have some evidence to suggest that not all teachers have the knowledge or expertise to be teaching literacy skill at all stages of schooling that they need to be," Hood said.
"But again I would emphasise it's a system failing. It's not an individual teacher issue."
Most teachers' colleges teach "balanced literacy" - the idea the children will learn to read naturally in a book-rich environment.
Lisa* said she was a teacher for more than 13 years before she learned how to teach reading effectively, after training in "structured literacy" in her own time.
This involves teaching letter sounds in a systematic way.
"If you say there's five children every year in that class who probably didn't learn to read, that's a lot of children that I failed, which is really gutting because it could have been my child, who's dyslexic.
"And that's not just one teacher who let down those children, it's multiplied around the country, year upon year upon year."
Lisa paid a private tutor to teach her son to read.
"Even though I had trained as a teacher, I didn't know how to help my own son."
Her school has now adopted structured literacy, paying for professional development and resources out of its own budget.
Many institutions were "clinging" to balanced literacy out of misguided loyalty to its founder, New Zealander Marie Clay, she said.
"It's a humbling thing, experience to have to revisit your practice, but this isn't about us. It's about our students and what they need."
It was during lockdown in 2020 that Wellington mother Ella* realised her son's reading struggles were more serious than she had thought.
"I was reading some of his stuff with him and he couldn't sound out three letter words and I thought this can't be right, he's been at school for a year and half."
Ella now pays $4000 a year for a private tutor to do a weekly session with her son and make up a lesson plan for the week.
He also uses an iPad in class to do an online structured literacy programme for which she also pays.
In two terms, he's gone from being unable to read three-letter words to reading books.
Ella was heartened by his progress, but she worried about other children who will not get the same chance.
"It does make me upset thinking about all the kids who are not going to learn to read using the current method of instruction - they just won't - and whose parents won't be able to help them."
The Education Hub report does not come down in support of either balanced literacy or structured literacy - it does not even use the terms.
However, it notes there is no system to ensure new advancements in knowledge on effective literacy practice get put into practice in the classroom.
Hood said that was a major problem.
"Literacy is a contested area and generates strong emotions in some.
"So there is not always agreement around how best to address the literacy issues.
"But actually things are so bad, I would argue we need to get beyond those differences of opinion and find a way to move forward."
None of the data in the report was new, she said.
"But so far it hasn't triggered that national response to say 'Hang on, things are in a really terrible state here. We need to do something'."
The reality was probably worse because all this data is pre-Covid and many students had now had two years of disrupted learning, she said.
