O, reason not the need!
(There we go, that's the daily Shakespeare quotation quotient out of the way
)
Like some others here, I work in a retail store, and I'm the only one who carries a knife at work. I don't really 'need' one, since the store is set up for everyone else to be able to function: box cutters in the back, scissors by the cash, and so on. I could use them if I wanted to
But when a courier drops a wrapped skid in the front of the store I'm the one who's first able to get the plastic wrap off of it, and breaking them down quickly is very important. Box cutters can slowly saw through nylon strapping, but I can slice through a half-dozen layers at once to transform it into manageable pieces. And when it comes time to strip cardboard boxes of old waybills and identifying stickers, having a better knife especially a small 'tanto' blade makes my job easier, safer, and more fun overall.
Another use for my knife that scissors or a box cutter can't do is elegantly opening product boxes with those fold-down flaps. I don't mean tape-breaking, but rather those pesky boxes with the thumb-press cutouts that crimp the cardboard, or the flaps that catch and tear. Slipping my knife in along the top of the lid, using the back of the blade to disengage the flaps and the flat of the blade to lift and open it, leaves the box unmarked. That's something that matters to me when I need to take a warranty card out before shipping a $500~$5000 item across the country.
But do I need a Spyderco CF Caly3 when I'm surfing the internet from my living-room couch? Um
sure.