From the articles I've read it's largely this. There are a percentage of kids that have other underlying issues that get in the way of learning in general, not

From the articles I've read it's largely this. There are a percentage of kids that have other underlying issues that get in the way of learning in general, not just phonics in particular. Dyslexia (which is often exacerbated by "whole word" methods), and ADHD (which is more often a food allergy than a real disorder that needs medication) do account for some. But in most of those cases it's a matter of... higher effort. Parents need to do more to provide the environment if they can, or hunt down and resolve the food allergy, or just push their children. School districts can spend more on qualified teachers. I'd speculate that 25% could be knocked down to 5% if we as a culture sat up and worked at it. But it requires a consensus reality, and broad alignment. Difficult. The best we can do at the moment is to spread the evidence and do right by our own children. (My mother was a K-12 school teacher in the Detroit school system for ~30 years. She's seen all the fads come and go. Phonics is not a fad; it works.)