It is incredible that there is still so much illiteracy... That is unfortunate, however, anyone can learn to read and write even when they are older. An example of this is the great Luis Mariano Rivera, who learned to read and write at almost 50 years old! So your friends can too, it is only necessary to create the alternative for them to learn.
I really believe that everyone has the right and we should be the helping hand to really help them, at least to encourage them to learn, I believe we can make a big difference in people and I know they can, thank you for your nice comment and your support.