To put a rough guess on some numbers, with a phonics-based program I reckon you will get something like 80-90% of kids to read, with a "whole language" one, abo

To put a rough guess on some numbers, with a phonics-based program I reckon you will get something like 80-90% of kids to read, with a "whole language" one, about 30% at best (though some more kids will end up reading because their parents hire a private phonics tutor, or do what your friend did). Kids with dyslexia or other disabilities affecting reading will need special help (this includes the case of kids who simply need glasses so they can see the letters properly!), and for some severely intellectually disabled kids, they may never be able to read. One of the promises of "Reading Recovery" (the non-phonics based approach) was that it would help the 10-20% who were still struggling despite phonics at school, and if it had done that it would have been worth celebrating. The problem is that switching to that approach in schools actually massively reduced the proportion of proficient readers.