In the name of Allah, the Most Gracious, the Most Merciful
If every single copy of the Qur'an in the world were to be destroyed, the Qur'an would still remain. How?
Simply because of the fact that millions of Muslims have memorized the entire text of the Noble Qur'an, completely 100% word-for-word, from beginning to end, including every vowel and syllable.
5 times a day, everyday, the Noble Qur'an is precisely recited from memory by Muslims in each of their five mandatory daily prayers, known as Salat.