Does it have to do with proper gun control or better access to mental health services?
- Mandatory military service makes people know how to use guns
- People have mandatory health insurance and social security, means there is no need to shoot people for money
- Less racist police, means minorities dont solve problems by themselves with violence
- high minimum wage, so nobody has to starve
- Gun owners do not use guns to defend against burglars, so burglars also dont have to use guns
- Proper handling of drug addiction (including addicts)
- better mental health because of mandatory holidays, parental leaves, and a lot of chocolate
- Prostitution is legal, so no pimping
Even European countries with a decent social safety net still have some drug addicts (mainly heroin) who are desperate for money to buy that expensive drug and will engage in petty crime to do so, e.g. pickpocketing, mugging, bicycle theft, theft of copper wiring, etc. (And yes, some states provide assistive infrastructure for addicts, but there are still demographics that avoid it and continue their addict to street drugs.) The fact that there is almost no shooting going on has more to do with legal and/or cultural pressures on guns than the existence of a welfare state making life OK for everyone.
Petty crime yes, mostly bicycle theft, and some mugging
They own them because they trust their government or if that's too strong of a word, they are content with their ability to defend Switzerland for the government. Instead of defending themselves from the government. (But that sentiment exists too)
And of course most pistols are not purchased for hunting.
So to answer your question: none of the above. It's demographics.
There's a lot of unrecorded relationships, but family and intimate partners make up a pretty big chunk of the homicides in the US.