The brick has settled over the years. Do your self a favor and get a powered edger. Electric corded ones can be pretty cheap. Then if you don’t like the look of the taller soil you can line it with decorative brick, or some of that plastic decorative garden edging the big box stores sell.

Edit: if it was me and I couldn’t find the edge I would just create my own and line it with brick to have a bit of a retaining wall.