The goal of preventative strapping of joints is not to limit movement, it is to limit the EXTREMES of movement.
The greatest property of strapping tape is PROPRIOCEPTION. It provides a warning signal to the brain that forces on the joint are greater than normal and an injury is about to occur. In doing so, it helps the body instinctively alter a movement pattern before more significant damage occurs.
Some strapping techniques are designed to limit movement where injury has already occurred. Where joints are already unstable, such as a grade 2 Lateral Ligament or grade 2 MCL sprain, strapping is used specifically to limit joint movement to prevent further damage. In these cases, it is highly recommended for both training and competition!