Defibrillation in adult cpr is important, why?

A patient's chance of survival from cardiac arrest due to V-Fib is decreased by approximately 10% with each minute that passes. ... Cardiopulmonary resuscitation (CPR) can delay the damage to the heart after cardiac arrest, allowing for a slightly longer time for effective defibrillation.

Defibrillation contrary to what people believe is not meant to "correct" rather is mean't shock the heart into systole, or no heart beat.

In cardiac arrest, the heart usually doesn't just stop but actually experiencing a lethal dysrythmia like Ventricular Fibrillation or Pulseless Ventricular Tachycardia, but it is trapped in that rhythm. The shock into asystole is meant to do one of two things; reset the heart and hopefully reset itself into a normal rhythm. If this is not the case then it actually makes BLS easier because your Cardiopulmonary Resuscitation techniques are the only solitary thing acting on the heart.

I'm not ment for this question