So why not remove this issue full stop?
Require people to demonstrate they know this before the can own a gun, make them responsible for those guns they then own.
The Swiss are still a good comparison, they have similar levels of ownership, with significantly lower levels of gun use in crimes. Yet the licencing system is not significantly different to the US.
The main difference is that they do actually gave a 'well regulated militia' as every citizen gets gun safety hammered into them during national service (and you remain conscripted in the militia until well into adulthood). So it seems that to allow large rates of gun ownership in a population works fine, as long as they are all well trained, and regularly retrained in safe gun use and ownership.
It's also worth noting that the Swiss constitution also has a right to bear arms and requires a well regulated militia.
I don't know ask those that would block that? Be it here or in general government.
I imagine it would be challenged in courts by those same people if it were made a mandatory thing. We the reason being it's a violation of the second amendment, and the main argument being that a mandatory safety class or concealed weapons class hinders their right to bear arms. However, that isn't the only issue potentially. The question then becomes would it be run by Federal outfits? Would it be a new requirement to FFL acquirement, if it is, would this then destroy smaller FFLs that don't really have the time to put into this. Would those FFL dealers get government support/funding to establish these classes, and not have to pay out of pocket? Since people already have to pay for a CCW (something every gun owner should invest in I think), would the price go up if it were a mandatory thing? Would you only be allowed to buy a weapon so long as you took the class that same day you were to become owner of it? Would you have to do this every time you bought a weapon? What about regions that don't have the ability to shoot certain weapons at indoor ranges and must drive miles out to open ranges?
While I think it sounds reasonable, I actually then stop and think well what is the downside to this that may put people off of it, and law makers more importantly. And that is the majority of what I see, and to me I think that's worth it, but others will argue it's not.
As for your insistence to [Insert this country here] as an argument, there is a big difference between the nation your using as an example an the U.S.
Military isn't mandatory service, sure you have to sign up for draft enlistment if it ever became a thing again. Outside of that you have no reason to worry about the selective services agreement when you turn 18, unless you plan to actively enlist. And even if you enlist, and get taught the strict gun safety they teach you in Basic (which is brief), it doesn't mean the attitude is that ingrained in people after. We know this because military members have committed crime just the same.
The fact is there is plenty of ability here in the states for people to have the knowledge to properly own, maintain, and practice the use of a weapon they purchase. And again it could be argued that many of them successfully do this. Those that do not have the right to not do that, but the question remains would doing such a thing still prevent these acts?