Filling a baby tooth

Why is it important to fill a baby tooth that will fall out soon anyway?
Children usually lose all their baby teeth before age 12. However, a filling is sometimes unavoidable before the tooth falls out on its own, for instance when a tooth is broken or infected. Besides harming your child’s oral health, a damaged tooth can hurt their self-esteem.
Procedure:
To stop the decay from spreading, the dentist must remove it with a metal instrument designed for this purpose. A filling is a simple, inexpensive way to treat a problem that could eventually cause pain and become very costly if not treated right away.
If no filling is done and the decay spreads, extracting the tooth may be the only option. In that case, a space maintainer may be recommended to keep enough room for the permanent tooth, since a missing baby tooth can cause the other teeth to shift. As a result, the space reserved for the permanent tooth will be taken up if nothing is done in the meantime.