If "guns don't kill people", we'd trust (good) people to wield cruise missiles. Clearly the weapons do kill people.
As for cruise missiles, those are covered by international treaty so outside the scope of discussion.
America also had a decline over the last 25 years.
What about hunters and people who use firearms to obtain some of their food? Not everybody lives in a major metro area with access to the latest food delivery startup.
I have neighbors who own dozens of guns. Some of them hunt. They don't hunt with the Gatling guns or automatic shotguns or any of the really impressive stuff. And yes, there are some pretty impressive guns in my neighborhood. But when they hunt, they break out a .308 or .30-06 or even a little .270. Bolt-action. Their hunting rifles carry 5 shells.
So let me offer a different answer. With what level of destructive power should George Washington have been trusted? Or Sam Houston? Is a cannon too much? With what level of destructive power should anti-Assad Syrian rebels be trusted? Or Ukrainians fighting a Russian incursion? Are shoulder-launched surface-to-air missiles a little overkill? If you lived on the Estonian border, what might you be willing to own in partnership with some like-minded neighbors? If you lived in a remote mountainous region and were surrounded one day by "officials" who shot your domestic animals, your wife, and your house without explanation, what level of destructive power would you wish to possess? Would it make a difference if that mountain was located in Idaho? Or Yugoslavia?
You trust individuals with F-22s and tanks. You trust BLM employees with sniper gear. BLM!!? You trust individuals with bombers and nuclear submarines and nuclear warheads. You may justify this as not trusting individuals, but those things are literally in the hands of individuals.
This month a SWAT team was called out against a local police officer. Both sides were trusted with major fire power including grenades and assassin robots, and with major defensive gear. If it takes a SWAT team to deal with a cop having a bad day, what recourse are the neighbors allowed?
Not really. Life would change for the better if the bad guys found it very difficult to obtain and keep possession of weapons, so the rest didn't have to play the arms race. Of course, since we don't know who's bad and who's good, that means everyone should find it extremely hard to buy and possess. Angry ex-boyfriends would then probably not be (fire-)armed unless they were, or willing to become, serious criminals.
The whole "responsible ownership", and "guns don't kill people, people do", argument also appears broken. It is not legal to own a cruise missile for example, so clearly the weapons themselves are the problem, and there is a level of destructive power beyond which individuals should not be trusted.
IMHO that level should be drawn lower; everyone gets crazy or depressed sometimes, we should reduce the potential for severe consequences.
And even an AR-15 isn't going to be much help against an oppressive government, as the tanks roll down the street, so the whole 2nd amendment argument seems very weak too.