Quickdraws in climbing serve many purposes, like attaching rope to protection during lead climbing, or keeping a path of ropes from tangling or sharply changing direction, which can damage the rope and jeopardize rope strength.
By using rock climbing quickdraws to secure together a path of ropes you’re also reducing rope friction, rope drag, and enabling more fluid movements as you climb. Quickdraws for trad climbing helps keep protection in place by preventing the rope from being pulled upwards. The best quickdraws for trad climbing are around 20cm in length.