EDC knives are used to variety of functions. Some people even dig holes in the ground in some rare situations with it. While we do not recommend using your knife this way, your knife can get blunt from normal but frequent using. EDC knives use premium steels which can really stay sharp for a long time, but good sharpener is always handy.
A sharp blade is a necessity for a knife. A dull knife can be much more dangerous than a sharp one. With a sharp blade, you are able to gently cut through food, without need of any extra force. On the contrary the dull blade is not able to penetrate stuff easily, you will have to use much more force and there is a risk that your knife will slip and you will hurt yourself.
How much does a sharpener cost?
In general, from 5$ to hundreds of dollars for premium ones. It’s not worth the money investing in a cheap sharpener that will not be capable of good sharpening or will broke down quickly. Better spend a little more and get a good one for 50 bucks than cursing about the cheap one that is not working.