ROC is a statistical tool to assess the accuracy of predictions. The accuracy of predictions plays a major role in how predictions would be used.
Quoting Prof. Andrew Ng, Stanford University, chief scientist at Baidu, here for reference:
"The difference between 95% accuracy versus 99% accuracy is between you sometimes making use of it versus using it all the time ."
ROC curves provide a visually appealing way to summarize the accuracy of predictions.