Because they use one-piece caps for both the edge and corner pieces. For stickerless cubes, you have to have two separate pieces for the edges (one for each color) and three separate pieces (one for each color) for the corners.
Because they use one-piece caps for both the edge and corner pieces. For stickerless cubes, you have to have two separate pieces for the edges (one for each color) and three separate pieces (one for each color) for the corners.