Other countries have less gun crime sure. They also have a functional health care system, including mental health care. They have culture that doesn’t glorify violence and better emphasizes connections with fellow humans and collaboration rather than confrontation.
Behavior like bullying that in the US often elicits a ‘boys will be boys, let them work it out’ reaction would get kids severely disciplined or kicked out of school in most other civilized countries.
Other countries didn’t defund their mental health systems in the 1980s, turning a great many violent and mentally ill people out on the streets. I’m not a big Reagan fan generally but that policy did irreparable harm to the US.
And other countries don’t treat addicts like criminals, locking them up for years with violent criminals where they themselves become violent. Other countries treat addicts like medical patients.

So yeah other countries do a lot of things better than the US, in terms of cultivating a less violent more inclusive society. You can’t just point to gun policy and say THERE THATS THE ANSWER THATS ALL WE NEED.