Why did Uthman ibn Affan, may Allah be pleased with him, burn 12 copies of the Qur'an and keep only one?

Uthman ibn Affan, may Allah be pleased with him, gathered the Qur'an into a single mus'haf to eliminate the people's disagreements in its recitation due to linguistic differences. Various mus'hafs had become widespread, such as the mus'haf of Ibn Mas'ud, Ubayy ibn Ka'b, and Aisha. As for burning the mus'haf for a valid purpose, there is no harm in it. Uthman did this while the Companions were numerous, and no one objected to him. The jurists have agreed on the permissibility of burning the mus'haf if it becomes old and worn out, to protect it from disrespect, while the Hanafis have opted for burying it instead of burning it.