Why do we need elephants in Temples?

Separating an elephant calf from its family and habitat, relocating her by travelling 3000 KM, tethering with a strong iron chain on temple premises, making loud music, bursting crackers, and shouting at it take selfie videos is cruel. What is more insane is believing that the calf is happy and dancing by swaying it head and trunk. 

Whether the calf illegally captured from the forest or it is a captive born is still a question. Whatever it may be, this is really cruel.