You have been fortunate. Many of the city streets I deal with were created in the 1800's. Curb and gutter in residential areas came decades later. Most of the first streets were dirt until brick plants could provide a ready source of hard pavement. There is little uniformity in sidewalk construction. Some of the original plats were on paper or left only wooden stakes that rapidly disappeared. The early surveyors did their best with the tools they had available and only concerned themselves with the tract required. They did not have the luxuries we have today to connect points at great distances from one another to ensure "perfect" alignments and measurements between the individual tracts first marked out. As surveyors came along later they had to make decisions as to whether to hold certain monuments as perfect or to use proportional methods or to ignore record street widths in order to keep a series of monuments aligned. A record 60-foot street may have variable width between block monuments, sometimes more and sometimes less than record. It is what it is.
We encountered a stone from an 1812 layout lying on the ground next to a newly installed utility pole. I was shocked at the ignorance of the utility company. It should be obvious that a cut stone with a drilled hole must a mark for something.
A report of the situation was made to the City Engineer and we asked what recourse can be had for such a crime. His answer was that the city would sue for the replacement cost and that may provide the needed education.
You bring up a great example of why the state societies and the national societies must educate certain groups of workers and the world in general. The DIG SAFE commercials that appear on television have awoken many average citizens to think about what is under the surface.
Monument preservation is very prevalent around here in ID and WA, particularly amongst the private companies. Most municipalities have no idea what the actual codes governing our monuments are. It's our duty to educate them. It's coming along fairly well but there are always new staff at these agencies that have no clue. In my primary state, ID, it is the engineers professional responsibility to accurately show the surveyed location of all monuments within the project area. We survey all of our own projects so it's not an issue. Most times, we are also responsible (contractually) for the replacement of destroyed or disturbed monuments. However, if the contractor goes off the grid and destroys corners not designated for destruction or replacement it is their responsibility to replace them. In ID any monument being replaced that isn't a PLSS corner requires a full blown record of survey.
Sounds like this would be impossible to do in non-recording states.