The US is pretty unique in its gun culture, and what do we have to show for it other than a bunch of dead people? We're not keeping any police or government forces in check with it, they're all armed with military grade hardware and could take a dump down our collective necks if our collective firepower were all that stood in their way.
The primary function of retaining an armed populace in the US is to defend the people against the government. On a local level, private gun ownership can look bad, but on a national level it's a powerful stabilizing factor. Having a few hundred million firearms out there gets people's attention. Look at Vietnam, Afghanistan, etc...military firepower isn't all it's cracked up to be against a determined opponent. It would be all but impossible to defeat a patriotic insurgency in the US, because
1. People are armed.
2. The government doesn't know where all the arms are, and there are too many of them to take them all at once even if they did know.
3. There are millions of people who would die defending this country from despots (at least ones they realized were despots).
4. Large parts of the armed forces would get tired of mass-murdering their own countrymen and would join or support them.
5. The entirety of the military's supply line would be in "enemy" territory. Ask Hitler how that went for him when he set up death camps in western Russia instead of arming the locals and pointing them toward Moscow.
Similar problems exist for foreign governments who would eye us- you can't infect an AR-15 with a virus, it's not damaged by EMPs, and it doesn't require electricity. Toss in good old American unpredictability (not a joke, btw), and we are the opposite of a tempting target.
But take away #1, and all that crumbles. Freedom isn't free, and gun violence is inevitable in an armed, heterogeneous country. It's a version of MAD- no politician who really tried to take over the US would stay in office long.
For now. Until we decay further. But I don't live in then- I live in now.
Note: I am not a gun owner, and I would never shoot anyone for any reason. I'm just talking about secular reality.