I think if he could already read and write it would be enough to understand Bitcoin. The school only gave evidence that he had never given the school gave no evidence he would master. So understanding Bitcoin crypto is not necessary to go to school, read, see and practice will make him understand.
Even though I never knew so far, is there anyone who can read and write without school. But as long as I'm familiar with bitcoin crypto, there are very few parts that I can use to get involved in crypto. I got more knowledge from reading and seeing.
Yeah just like how all students are forced to learn all subjects, not all students are interested with math, language, art, physical education etc. When they're not interested and forced to learn about the subject, they will not be focus and actually don't want to know anything about it. Some people didn't even become rich too because they're live in this world isn't for materials goals, but only to achieve their religion's goals.