In my area we have accepted that grass fires are fightable, but structure fires are not. We don't have the equipment or training to enter a building. In '15, folks in the community had to decide whose house to sacrifice. Luckily BLM showed up in time with a helicopter and a bucket.
I'm on the volunteer fire team and our first line of defense is indeed the lawn sprinkler system. Then comes the ancient, antiquated donated fire trucks and decommissioned gear. Our last line is renters' insurance. Firefighting is a time-consuming, expensive business for rural communities, and a little scary when you know the coat and pants are older than you are and the water pressure in the hydrant might be too low to fill the hose. The shed where I keep my rock equipment has partially burned and been rebuilt twice now in twenty years- once from an electrical fire and once from a wildland fire. Any given summer may take it for good and me on top of a brush rig with a hose can make an effort, but won't save it.