Those who can’t read can still learn to read, while those who refuse to read will become unlearned.
Through reading comes knowledge. Through knowledge comes growth. Without knowledge, our growth is severely impeded. This is not to say that one can’t learn outside of reading. Throughout the centuries, many people who never learned to read still led productive lives. However, their knowledge was limited to what was at hand (people, places, things, ideas, etc.). The ability to read allows us to surpass those limits. Not only does it open up the entire world, but it also grants us access into the countless worlds found in the imaginations of others. Worlds filled with magic and adventure. Worlds filled with aliens and mystical creatures. Worlds filed with beauty, the likes of which cannot be seen on earth. Reading opens up to us the worlds created by people from across the globe. People like, J. K. Rowling, Jules Verne, and Mark Twain.
By refusing to read, one can become narrow-minded. They can become closed to new ways and new ideas. For centuries people have written down their knowledge (one person can’t know everything). They wrote down their experiences so that others could know and learn about them after they were gone. By refusing to read, one can never know about these people. Sometimes by reading how other people reacted to a situation one may avoid having to make their same mistakes - possibly even a fatal mistake.
Those who can’t read live in a small world, but they haven’t closed off the possibility of someday venturing outside that world. Those who refuse to read have fenced themselves off from even leaving their small, lonely world.