Given your premise, I'll submit that while guns are efficient, they are also noisy, require ammunition and regular maintenance, perhaps parts which may not be available. This would not be a desirable position to find oneself in.
There are alternatives which are much less likely to attract unwanted attention, and are also more likely to put food on the table than a gun. So no, I would not rely on a rifle or other firearm as my first choice for any number of things, but would have one (or more) for those occasions in which a firearm is warranted.
My logic is simple: Relying on a single thing or method for accomplishing some task, unacceptably limits your options, and is foolish and shortsighted.