What can a plain edge do that a serrated edge can’t?
Serrated can cut some things a plain edge can’t, but a plain edge can’t necessarily cut everything a serrated edge can… Or if it can, it will be tougher to do so. However, it’s been said that a plain edge will make a “cleaner” cut. But, you can slice with a serrated edge, as long as it’s sharp, with a push cut, and the cut will be as clean as with a plain edge. Serrated edges also stay sharp a lot longer… So, what advantage are you getting from a plain edge?
You have more control when making any kind of delicate cut as you have an edge that is on long curve rather then many curves. It is easier to change the direction and/or angle of the cut while in process of cutting. Serrated edges have multiple thicknesses and lots of points to drag, punch through or shift the angle of the cut this makes the cuts much rougher then it might seem. While a plain edge may tend to dull more readily it is also very easy to resharpen compared to a serrated edge.
I’ll simplify it for you…. scapels are plain edged. Professional chefs and butchers pay hundreds of dollars for knives with plain edges and if any profession is hard on knives those two are. They know its better to have to touch up the edge in a few seconds a couple times a day then to spend hours doing it once a week. Heck even the people who compete to cut free-hanging ropes and the swordsmen cutting rolled up tatami mats in the Japanese style sword cutting competition use plain edges and the swords for one tend to rarely ever need sharpening.
GTA IV Broadcast : On CNT : The Serrated Edge