1. It was written under the assumption that there would be no standing army, so the citizen militia would be the backbone of the defense of the nation. But that isn’t where we are today, unfortunately.
2. A large part of the US seems to believe that getting rid of guns would make the US less violent. I suspect they are completely wrong about that. Our National myth is about using violence to successfully solve problems, from the original revolution through our successes in several wars.
So we are stuck with an extremely divisive issue which really has no impact on anything real.