Markers only mean something on variety coins. If the coin is a variety, then the markers have not meaning. On markers it is best to find at least two to confirm a die, but the absence of all doesn't disqualify your variety. It just helps confirm die state. Events happen to dies that alter markers. Some appear for a while and then flatten out in the fields. But up close to/inside devices last a lot longer. Die cracks/breaks/scratches must be an exact match or missing some detail on die scratches.
Die Deterioration continues to get worse as the die ages.
Die clashes can be polished off creating new die scratches. (Over older ones usually)
Die scratches flatten in the fields as the dies start to age.
Die flow appears in the LDS to VLDS dies states and shows more die wear on coins that are struck on a die that is reaching retirement.