I can’t disagree - development usually bring in truckloads of topsoil. I’ve got a neighbor that grew up here before the development was built - it was a quarry that separated the rocks from the rest. The rocks stayed, and the clay/sand/gravel was sold.
Having just ripped out the old (non desert-adapted) lawn - and then spent months tilling, leveling, and prepping the soil, I’ve spent a quite a bit of time working over every square inch. I’ll have to do a soil jar test this weekend… I certainly have piles of it laying about.