People use this machine-tool to work on wood, plastic, metal, glass etc.
Abrasive belt allows to wear off materials, and the polishing disc is doing just what you think it should do.
This mid-poly model was modelled in blender with mixed techniques, textured in both blender and Substance Painter.
Tris: 157 549Verts: 79 610Faces: 78 258
If you do not like the wear on the model, just use a solid color instead of a texture. It looks good anyway.