Cell phones that are carried inside pouches or holsters are always exactly where they are supposed to be at the exact moment that they are needed. A pouch that clips to a pantsline or loops onto a belt ensures that the phone is always close at hand, never in a mystery location. The same cannot be said of carrying a cell phone around in some type of bag or purse. By the time you actually find your cell phone, the caller has already started leaving you a voice message.
Toting a cell phone around in a pocket used to seem like a pretty good idea, but that was before smartphones like the Samsung Galaxy SIII reached gargantuan proportions. Placing one of these large cell phones inside a pocket is impractical unless you don't mind the phone digging into your leg when you sit down or, in the case of particularly loose jeans, banging against your leg insistently with every step. Carrying a cell phone around in the pocket of a baggy pair of pants virtually ensures a bruise on your leg by the time you're done with your grocery shopping. A cell phone pouch eliminates the discomfort and inconvenience of these other methods of carrying your phone.