Sam Blumenfeld use to speak at home school conferences I went to when my kids were young. I remember that he didn’t believe dyslexia was a real thing. I heard him say once that if someone was really reversing the order of letters in his brain, then why did they not bump into the wall next to a door when trying to go through it.
In any case, I did use his book to teach one of my children to read and had great success with it.
He said contemporary educational media such as Sesame Street was probably actually causing a form of dyslexia, what with blue monsters jumping out of trash cans and all while children were trying to learn their alphabet.
RIP