I’m not American (Scottish actually) but allow me to put these points to you.

Plenty of countries in the developed world allow you to own firearms, your idea that this is unique to America is wrong. Switzerland for example requires every able bodied man to own an assault rifle as part of their conscript-défense system, and yet their murder rate is negligible. Canada too has higher gun ownership per capita & yet a much lower murder rate, the reason for this is that there are far fewer Africans in Switzerland & Canada. Firearms were legal all across the UK until fairly recently, & yet now with them being banned guncrime is increasing, yet again due to there being more Africans in our country...

The reason a lot of Europeans (including myself until I looked into it) have these misconceptions is because of the Americanisation of our media & politics & the bias nature of the media in America itself. Hence your average Brit linking US murder rates to gun ownership & ‘fat obese hill billies’ rather than dumb, criminally-prone blacks.

Most of the rest of the developed world doesn't have to deal with a very real reality of getting killed by some mentally ill depraved beast

Mentally ill people kill in every country in the world. Whether it’s done with a gun or a knife or their fists doesn’t matter to the families of the person killed.

you can argue about the rarity all you want but when it happens it happens, you or someone you love is dead

But if you’re talking about what should be national-policy then of course you have to care about the rarity (or otherwise). Not basing policies on statistics is going to lead to poor decisions.