With rare exceptions, modeled polygons don't look like physical plates unless you go to the considerable extra effort of modeling seams between them, rivets or other visual cues that are much more easily accomplished with textures. Even if you're just doing some subtle shading differences, it's usually easier to do it with textures. On Polaris
for example, I don't think there's a single panel line that just happened to fall along an existing set of edges in the 3D geometry. The only reason I didn't
use regular mapped textures is because I already had the modeled panel lines and because UV unwrapping this thing is not gonna be a task for the faint of heart.