Learning advanced knife skills not only increase your professional worth, but it gives you a lifelong skill that will always be useful. Beyond the basics of holding a knife, holding food, and being safe, furthering your skills will allow you to work faster and more efficiently.
You must be able to make uniform cuts. Some foods you cut have fat areas, thin areas, and everything in between on one piece of food. The average Joe slices it into pieces that vary in size and width. Then the larger, thicker pieces take longer to cook than the small, thin pieces. Uniformity ensures that you have predictable cooking times, evenly cooked food pieces, and better aesthetics.
Aesthetics are another critical skill that cannot be undervalued. From the pleasing sight of uniform planks to decorating knives that give your cut watermelon an edge with patterns, a pleasing dish can wet someone's appetite as much as smell. Garnishes also go a long way in the aesthetics of your plate and properly cut garnishes are crucial. A chiffonade cut vegetable leaf or a brunoise diced garnish can take your plate from good to great.
Finally, you must have a versatile arsenal of cuts and understand each. This goes hand-in-hand with aesthetics. You cannot enhance your plate with a brunoise garnish or a chiffonade leaf if you do not have chiffonade and brunoise cuts in your toolbelt.
Different cuts help you cook accurately as well as aesthetically. You need to know what cut is appropriate in any given situation. Uniformity, aesthetics, and variety of cuts are the trademarks of an advanced cook with advanced knife skills.