I do not think this is sane mapping, e.g. here Node: 1423904509 | OpenStreetMap or in your other examples. Even more when there is no crossing infrastructure tagged, just “kerb”.
In cases like here: Node: 7040984425 | OpenStreetMap
it is easier to understand, as a crossing feature is present.
If the crossing way is drawn, I would expect the kerb to be at it’s actual position, e.g. like this: Node: 12188197920 | OpenStreetMap