At the end of the day, It's just math.
It took me a while to understand how to manipulate texture coordinates and recreate organic looking materials using Blender's various nodes such as Voronoi and Musgrave textures.
Infinite detail and variation at the cost of speed.
The advantages compared to manually painting textures are many but they come at a performance cost. It's easy to make details that become invisible when seen from a distance. But the freedom to control every aspect of the shader while modelling in Blender is superb.