Training for muscle builds muscles, joints and ligaments and gives you a strong structure however just training for muscle building can be very one dimensional. You may become strong at moving a single muscle within a small range of motion but you will end up neglecting the rest of the body and it’s holistic nature.
Training for performance on the other hand allows you to exceed in a skill set and you will gain muscle to perform, your nervous system will stimulate to give you new brain and motor skills as well as muscular endurance to continue performing the skill set repetitively. It will also boost your confidence physically as you get good at a skill set and can measure yourself getting better, faster and stronger giving you a sense of achievement after each session.
Another thing to consider with performance training is that it will challenge your weakest links and working on them will allow you to develop new strengths, movements, skills, muscles and forms of fitness.
Building muscle is limited to the muscles in our bodies whilst performances has no limitations as the mind can develop countless skills for countless movements, exercises, sports, activities and lifestyles.