For europeans:
1) Consider firstly, that the continental US is about the size of *ALL* of Europe.
2) Consider secondly, that there are
vast tracts of this territory that are completely uninhabited. (Owned by the BLM, not for sale, and non-negotiable.)
3) Consider thirdly, that due to the above, there are 'rural' areas, and then there are "Practically in the damn wilderness, dont bother trying to call police, there are no god-damned roads." areas.
Unlike the smaller nations of Europe, which can manage an effective state level police force, these vastly underpopulated areas of the US cannot sustain such. (See for instance, Wyoming in the linked map. See that tiny population? Do you REALLY think they can sustain a robust state-wide police? Did not think so.)
As a result, there *ARE* areas in the US where you REALLY DO need to have a gun for personal safety reasons. It is not against humans, it is against wild critters that might take a liking to either eating YOU, or trying to bust into your cabin, and eat your cached food supply, tearing the place up in the process.
The debate in the US mostly comes from areas with dense population (NY, FL, CA, and pals), where there is dense urban populations, robust police systems, and other civil security apparatus in place--- where it really DOES NOT make even the tiniest bit of sense for the people there to own or carry firearms--- vs the areas where, if you take those firearms away, PEOPLE *WILL* DIE. A LOT.
Sadly, there is also a large demographic that uses this latter group (People who genuinely do have a need to own and carry a weapon, because there literally are no cops, forest rangers, or other state security service providers--- AND lots of wild animals) as an excuse to try and own their own anti-tank weapons, trying oh so desperately to conflate the two. The NRA often riles up and inflames this group, since this group is among its biggest customers/supporters.
There is also a very large demographic that does not know jack shit about guns (in general), who is terrified of even the very idea of a gun, no matter how tiny, or how well trained the private operator is, and so desperately want to get rid of *ALL GUNS*.-- Nevermind the poor bastards that don't live in the urban areas. ("They should just move into the city like sensible people." et al.)
Because the political climate in the US has, for the past 50 years, been on a downward spiral of ever greater degrees of isolationist ideological position taking, there is very little progress toward a 'sensible' solution to this set of problems, and instead there is a festering boil, where people get shot all the time in urban areas due to excessive availability of firearms, constant drumbeating by the NRA, and people who just want to be sure that they still have food before the snow falls and blankets them in for the winter by keeping the bears out, or who want to keep the reintroduced wolves from killing this years calves in calving season-- and nothing but rage and spittle flying in every direction, with finger pointing, name calling, and zero progress toward an actually effective solution.
Europe is much older than the US is. Human populations have had CENTURIES longer to establish territories, roads, cultures, and the like. The social infrastructure is much deeper and better established. This is why you Euro people have a hard time understanding the concept that yes--- There really are places where you really do in fact need to carry a gun to be safe from carnivores in the US. Such places really dont exist anymore over there. They very much exist here.