tbh the Us design philosophy was all about bombing survival hence suburbs are quarter acer plots spread out over miles.I actually know a bit about this. US construction materials for almost everything except few skyscrapers in the urban core is wood, either full wood or wood with concrete first floor. Concrete first floor, rest wood is called 5 over 1 and is the predominant multifamily housing unit in the US since the 90s. Otherwise single family homes are full wood. Many "concrete" or "brick" building in the US actually uses wood as the primary load bearing structure and interior while the brick or concrete is a facade used to resist weathering, waterproof the building, and to make it look more expensive and high end.
If you assumed day light ww2 style bombing raids the plots are spaced far enough apart that a bomb hit on one house would not likely kill another. Also the yards serve as fire stops inhibiting fire storms as do the frequent roads . There are a lot of weird benefits to suburbs and sprawl from a war time perspective . Assuming you do not expect to fight on foot . Tbh even than it still creates a hellish eco system where nothing is cover and everything is concealment .