Look at how a good set of plans handles water flow on a site. A drafter who spots a low spot that would pool water near a foundation saves the builder from a call in two years about a wet basement. That's not just a drawing, it's stopping a future lawsuit over mold before the first shovel hits the dirt. The lawyer gets involved after the damage, but the drafter's line on a page stops the damage from ever happening.
Y'all ever had to explain to a GC why you moved the driveway six inches over just to hit that low spot? I've been on jobs where water was literally pooling against a foundation we hadn't poured yet, and the builder was like "just angle the grading." No, man, you fix the flow on paper or you're patching walls later. @cameronschmidt hit it right - the lawyer never sees the work that saves their paycheck. I've got a folder of old plans where I caught stuff like that, and the homeowners never know they dodged a bullet.