Just wanted to share how you can use the remesh modifier to add a non destructive old and worn look to your model without adding more triangles.
In these examples i made a window frame, to make such a frame use lines/curves and add depth to them then add a curve profile ie the built in cornice molding, then convert to mesh, i also extruded out some faces to get the grid shape and added some bevels to those. Make sure to use mirror modifiers or symmetry to make your life much easier.
Anyway to the point, if you want old worn wood look, use the voxel remesh first then the decimate collapse which brings the triangles count right back down, you can adjust these however you like to add more fine worn detail if you dont mind the triangle count going up.
Tips try adjusting the adaptivity of the voxel remesh to get more or less details, and try turning on and off smooth shading. The initial voxel size with no adaptivity i used was 0.0075 which gave about 200k triangles as a good starting point.
WARNING NEVER MOUSE PAN on Voxel Size it will consume all your ram and resources and freeze Blender as it will try to generate a very small voxel size with hundreds of millions of triangles.