Movement is essential for brain development and bone health. Gymnasts learn body and spatial awareness. They learn how to tighten muscles, how to stretch.
They learn co-ordination with many cross-over exercises which are critical for brain development. They are taught to use both sides of their bodies, to stretch on both sides, to cartwheel on both sides.
They learn balance, strength and flexibility, muscle endurance, all necessary for a life free of issues like back pain, etc.