There are many uses even for those who have no desire to compete. Firstly, practice of forms builds the basics of martial arts. In any style learned. Beginning with on stance, then a technique later stringing them together into lines, and eventually full sets. No martial artist can progress properly without proper attention to basic techniques.
Forms develop these skills to ready the practitioner for trials ahead. Beyond this form practice is an incredible cardio vascular workout; it pushes the athletic potential of the body.Mental focus is also developed. Learning sets of complex maneuvers is a great mental task, and increases mind body coordination and opens neuron-pathways. Coordination, balance, speed, strength, flexibility, timing are just a few of the qualities which set training reinforces.