A failing wall can damage somebody else’s property
Retaining structures hold ground, and when one fails the consequence lands downhill: a neighbor’s yard, a neighbor’s house or a public road. That is a liability claim against the owner of the wall, and it can be substantial relative to anything else on a modest property.
Steps and drops produce ordinary injury claims
Uneven original stonework, steep steps without rails and unfenced drops are the everyday version of this. A visitor, a delivery driver or a neighbor’s child falling is the claim most likely to actually happen, and it is made against the household.
The exposure is larger than the property value
On a house in this value range, standard liability limits were set with the building in mind. A serious fall injury or damage to a neighbor’s home is not bounded by what your house is worth, which is the argument for a layer above.