Why doesn't Europe suffer with gun crime anywhere near to the extent of the US?
I'm not American. I don't wish to dictate US policy on this. I understand why people might feel they need arms in the US (almost a domestic arms race). There are a lot of guns in the US, and any process of disarmament would be risky and probably impossible at this point. You just can't extract them from the USA. There's no magic switch.
Guns are still accessible in Europe. It's still possible to get them. Criminal gangs do this, but we still don't get anywhere near the same level of violence with them. And no, knife crime does not make up the difference. US murder rate is much higher than UK:
https://www.nationmaster.com/country-info/compare/United-Kingdom/United-States/Crime/Violent-crime
So why is this? The adage here is "There's no way to stop this" says the only country where this happens.