You can build a face frames for cabinets with stile and rail construction without using Cope & Stick. Stiles and rails can be butt jointed with square cuts. Most home built cabinets are built this way.
The Cope & Stick method is a more elaborate, more professional construction method, requiring special matched (female and male) shaper or router bits. These are especially nice on a frame and panel construction.
The price of a matched cope & stick set has actually come down in price over the last 30 years. And more of these cutters are now finding their way into home woodshops.
Thank Goodness for that.