Scissors are faster and safer than knives for:
-accurately cutting fabric, tape, gauze pads and rolls
-accurately cutting string and thread
-cutting small diameter wire and cable
-stripping wire
-dicing up carrots and celery
-rapidly reducing big twigs into small twigs
-cutting your clothes off when you're really tired
-making paper snowflakes when trapped inside on a rainy day.
-trimming hair
-trimming candle wicks
-cutting light sheet metal and plastic
-getting past airport screeners and police stops.
-peeling the foil off the champagne bottle in your rucksack