Note: when you put the barrier=kerb tags right on the intersection between two perpendicular sidewalks (such as https://www.openstreetmap.org/node/9811659110 for example) it implies that someone walking along the sidewalk and turning directly onto the other has to step off the curb. In reality they never encounter a curb at all unless actually crossing the street. It's generally better to map the curb a little bit away from the intersection, where the crosswalk crosses the actual curb.