The most important part of your comment is something you hinted at in the last paragraph. Reading ability alone means very little in a practical sense. Reading

The most important part of your comment is something you hinted at in the last paragraph. Reading ability alone means very little in a practical sense. Reading ability is an implicit task of basic cognitive functioning like following simple instructions, interpretation, pattern recognition, prioritization, and so forth. It’s frightening how well many children grasp these skills well and how many adults struggle with these on such a very basic level. For example, in my line of work as a front end developer there is a thing called the DOM, a tree model. Many small children understand tree models and can navigate them with ease, but many (perhaps most) adults cannot do this on even a primitive level and do bizarre things to protect their careers in an effort to learn how to navigate the DOM which only requires a few hours of practice with absolutely no barrier to entry.