Defense from crime and abuse is a task undertaken by governments in basically all civilized countries.
You have laws that set clear boundaries on what’s allowed, courts whose job is to enforce those laws, and a police force that is trained to use weapons if needed in order to protect other citizens from law abusers.
Civilized societies are shaped around such separations of concerns and accountability - something that you don’t have if every citizen feels that they have the right to pull the trigger whenever they like.
This is how things have been working at least since the times of the Greek polis and the Roman empire.
If you mistrust institutions, elected governments and police forces to the point that you feel that you have the right to take care of yourself however you please, then either you have a problem with rotten institutions, or a mindset problem. Either way, your idea of advanced civilization was already outdated 2500 years ago.
And you can’t see that if you’re the only country following these principles, and you’re the only country with a major gun violence problem, then probably the problem is with your country, not with everyone else.