If no civilian can buy a gun in your country criminals also can't unless they put in more effort. Thus there is an increased barrier to them having one which reduces the numbers of guns criminals have and thus the number of gun incidences.
In Germany you were able to buy a few illegal ones from the Russians at some point but they are gone since almost 2 decades. Now you have to travel to different countries and know people there. The common thief wouldn't put in that much effort or simply not be able to. He could also join a sport shooting club or study to become a hunter or cop. All not very likely scenarios and that increased barrier and reduced likely hood shows in the gun violence statistics.
Still I prefer freedom
but wouldn't call the other approaches fools without trying to understand them and maybe aknowledging aspects which are good.
Guns don't wear out and we have more than one gun for every person in the US. We didn't get disarmed after WWII, or ever. Much like Switzerland of Finland. Criminals in the US get guns through theft, the porous borders with two other gun owning countries and the guns that they are legally allowed to buy before they became criminals. Short of a 2/3 majority voting to disarm the nation door to door, guns are not going to suddenly be hard for criminals to get.
US public policy has to embrace the fact that guns are here to stay and find the best ways of coping with that, rather than pretending we can become Japan.