Amateurs work until they get it right,
Professionals work until they cant get it wrong.
Gives you the ability to specify exactly what you want to emphasize. Your focus may be on losing weight, changing body composition, getting strong, improving conditioning, body symmetry, mobility, or stability. Your points of emphasis may change as your training evolves.
With individual training, you determine the specific points of emphasis in your training at all times instead of following a generic training program designed to accommodate multiple individuals in a large group setting with the primary purpose of earning a large profit with little regard to what you want or what your body needs.