LOL what a stupid argument. If someone cannot read and write how are they going to use Bitcoin anyway, regardless if their wallet uses seed phrase as a backup or not, come on! Also, 8 billion people should not be using seed phrases because a few million are illiterate? Since when we level down in technology? Perhaps we should also stop driving cars because blind people cannot use them? Or maybe let disable or encryption because most people don't understand cryptography? Get lost.