Why Did the Indians Replace the Maravingians?

The carolinians formally replaced the maravingian dynasty on the throne by the mid eighth century. But that shift in power between those two dynasties, didn't happen overnight. Of course, pippin's ancestors had been mayors of palace for several generations. The mayor of the palace was originally meant to just manage the royal household. As time went on, more and more responsibilities and duties were added to it. It effectively reduced the king himself to little more than a figure head.