This is the reference photo I've been using, and after a few attempts at it myself I wasn't able to get anything I was happy with.
Essentially I want to be able to add an image into the Shader node network (or Compositor), change the seed, and have a result similar to the reference.
I'm sure there is an answered question or a tutorial for this kind of thing, but I've looked around quite a bit and couldn't find anything.
There is several types of cracks and scratches in your reference image ... some are easier to handle than others.
The simplest ones "empty maps" ... the key here is probably Musgrave texture node with low Dimension value ...
Secondly cracks that can be handled by Voronoi texture ... here it comes very sensitive in therm of value setup to get wanted result ... so something like this ...
Value node is used in "Seed" meaner.
Small painting cracks, seen at hairs (right bottom side), are the most difficult for me, but some similarity can be achieved by Voronoi > Minkowski ...
The trick to generate lines I could use Mapping node with some translation, but keep the nodetree light I used slightly different Randomness to let Compare node do its job.
Voronoi > Minkowski seems to be useful for other kind of damages - liquid or mold things (usually tinted to to brown paper) ...
With a small change of Scale value (here from 1 to 2) became like a paper damage, that can be used for Transparency and Normal factor ...
... final combination of those structures depends up to you :)
Before
After
To give final result a bit of thickness for cracks and creases you can combine all types to be reused into Height map
