Smartphones are very powerful. They are so powerful that the FM capabilities inbuilt can save lives. Most of what they do is through a cellular connection. But cell towers are vulnerable during floods, tornadoes, hurricanes, wildfires, and other natural disasters. At other times, there could be network congestions because of too many people making calls and this could make communication difficult or impossible.
Through FM radio, emergency management agencies are able to convey evacuation instructions, alert communities about emerging threats, and also this medium can be used to coordinate relief efforts.