Because you do not live in an action movie, you will not be able to stop them. You will not know they are coming, or when, or know how they intend to do it, et

Because you do not live in an action movie, you will not be able to stop them. You will not know they are coming, or when, or know how they intend to do it, etc. If you are well-defended with arms, they will simply use some other method. Having a shotgun does not make you significantly harder to kill in modern society. It would make you harder to kill if we were limited to cinematic tropes like declaring when we intend to do it, how we intend to do it, etc, sure, but we don't live in that world. We live in a world where the only thing that prevents our death, every day of our lives, is that no one nearby is willing to kill us. Some people find that scary, and it may seem like a shaky thing to stake your life on. But, firstly, you have no choice. Secondly, it works for billions of people and has kept us safe for tens of thousands of years. Even after we developed the knowledge, tools, and ability to kill millions at the push of a button.