Have you ever taken….. a stats course? And do you ever…. read the news?
Your first assumption is that the rest of the world doesn’t have a “gun violence problem”. This is false.

Anyone who does any stats at all knows that when frequency is dependent on population, you need to normalize for it. Well, when you do that, you find that deaths by mass shootings (which is really what this conversation is about) is actually lower in the US than in several European countries; we’re actually kind of middle-of-the-road.
So, I’d suggest you rethink your conclusion that “the rest of the world doesn’t have a gun violence problem.”