Composite is a mixture of leather and artificial material, making it cheaper to produce than real leather material. But composite-made basketball is very lasting and durable. On the other side, real and complete leather-made basketball is more durable because it doesn't have artificial materialization.
Furthermore, a complete leather-made ball is pretty consistent with bouncing and accuracy. You can achieve the level of perfection in grip as well. So we can say that a full leather basketball is better than a composite-made ball.