Why do you smoke a pack of cigarettes and only tear the first half of the tin foil?

Why when smoking a pack of cigarettes, open the tin foil paper of the cigarette case and just tear a hole at one end to shoot a cigarette? This should start with why tin foil paper is used for packaging.

The tin foil paper wrapped in cigarettes (aluminum film composite paper is used in modern times) plays a sealing role, preventing cigarettes from being damp and moldy, and protecting the moisture and spices of cigarettes from leaking out in a short time. Therefore, the tin foil should be used as soon as possible after tearing, and the smaller the opening, the better. For the convenience of users, the manufacturer pressed out the tear line at the opening position.

As a user, of course, you don't want to see an open pack of cigarettes messy and inconvenient to take, but a small opening can keep the cigarettes from falling, messy, and the cigarette case from being deformed, and the order of taking them is orderly. A small opening brings a lot of fun to smokers. You can shoot, hit and shake two pieces at most, and you have no scruples about throwing them all over the floor. You can't play so many tricks with your mouth wide open.