Most suburban rear boundaries face another household. Here a great many face the dunes: open, publicly reachable ground with no lighting, no residents and nobody who would have any reason to look at your fence at eleven at night. Anyone standing at that boundary is doing so unobserved and unhurried, which is the exact condition that makes hardware carry the load rather than share it.
The dunes also move, and that is a genuinely practical complication rather than a poetic one. Sand accumulates against boundary walls and gates over seasons, and a gate that swung freely three years ago can be sitting in a drift that stops it opening — or, more usefully to somebody on the wrong side, gives a step up that was not there when the wall was built. It is worth looking at that level periodically rather than assuming a boundary is what it was.
The third factor is what the same sand does to mechanisms. Gate locks, padlocks, sliding door runners and garage tracks on this edge fill with it steadily, and the wear is abrasive rather than corrosive. Things do not rust so much as grind, and the outcome is hardware that becomes progressively harder to operate until a household quietly stops bothering — which is when a lock repair visit stops being maintenance and starts being a security matter.