Metal cookie cutters have so many benefits that make them a clear winner when it comes to ease of use and durability. For one thing, metal moulds are sharper and sturdier. You can use many times more force on metal cutters, and they will be just fine. But plastic cutters do not withstand that much force. Beyond a point, they will snap and break into many pieces. The fact that the edges of those moulds are not as sharp as metal moulds even compound this problem as you will need to put more force on them to cut the cookies.