The simple answer is yes.
Laws now require helmets in many areas.
Many thousands more suffer less severe but still debilitating injuries which are far worse than the physical pain of scraped skin or even broken bones. Your child can suffer permanent personality changes and learning disabilities from a brain injury, and both of you will be aware of what they have lost. Common long-term effects include concentration difficulties, aggressiveness, headaches and balance problems. Imagine your anguish if this happens to your child. A good shop helps with fitting, and fit is important for safety.