What I like to see in materials:
- Some solution to large tiling areas – using world-space coordinates to look up into a noise modulation or similar.
- Multiple materials that work very well together in the same class – not just one “wood” texture, but five or six with variations in knottyness, smoothness, etc.
- Landscape materials that use the height and color layers to create good-looking blended terrain.
- Pre-calculated micro-level ambient occlusion
- Physically accurate gloss/roughness maps and normal maps
Actually painting the base texture isn’t that hard, even for me as a programmer. (I can always use Filter Forge 
Making materials that actually work is a lot harder, and where the real value is IMO.
Also, I’d be careful about displace-based materials – those could be too expensive to use for most games on most targets.