I think that it’s the little bits of polish and small details that can really make a model more than just a box and lines with texture fills: I often add details like skirting boards to walls, roof hips and valleys, … and it probably works out that the majority of the surfaces and geometry in my models is generated from the detailing stuff.
If you look around, about half of every-day, real-life objects have some sort of “enhancement” to the edge; sofa has piping, jeans have stitching, the TV has a surround, the keys on my keyboard have an edge, the walls in my room have skirtings and coving, a window has a frame, the radiator pipe bend has a weld, etc, etc…
It would save a huge amount of work and model size if I could just select an edge and add a texture rather than modelling it:
Using PNG files (with transparencies) I can think on hundreds of applications, from lines on a road to riveted metal sheets. The attached mockup has screws, drips, groove, edge enhance, corner stones, grass, cobble edge and muddy ditch:
The main problem I can think on is how to export the fill; maybe each one has to be made into a “unique texture”?