Well ya but house fires are rare. Especially newer homes so.Once it rolls up the wall and gets into the overhang and attic its on. Those fires require an aggressive attack and a lot of competent manpower to knock down. There are a lot of times where the building it originated in has to be written off and the resources directed at the exposures.
Remember a fire has to burn through the interior drywall, then ignite the sheathing, and burn through the cement siding, then get into soffits of the adjacent unit in sufficient amounts to ignite the framing inside. It's not easy to do. It's why they're allowed to be built as close as they are.