Binding the joint between the sides and top-back creates a stronger connection and adds a stunning accent. Here Chris is using maple to bind the guitar.
“The Binding acts as a way to protect the end grain of the wood. It caps it off and adds strength to the perimeter of the body. It acts as a bumper to prevent a simple ding on the edge of the body from turning into a split in the top. “
So, yeah, kind of important.