Bismillah
Thank you for your question. The messages of the Torah and the Injeel were messages for specific times before the final message of the Qur'an, and so the existence of these three books is not a question of God's perfection, but the imperfection of the human race and its propensity for change. Further, neither the Torah or Injeel were preserved in their original format and so the revelation of another message became essential, which is now preserved for perpetuity.
May you always be successful