The smokes fall out easier from a fully opened pack and random junk can fall in. The proper method is to tear off one side of the wrapper. It’s easier to get just one smoke and you can keep the rest of the smokes bundled together by crushing the empty bit a little as you go through the pack. The less the smokes shake around the better the tobacco stays packed. (It makes it look cooler too when offering someone else a smoke like the attached picture.)