you say the lions share of murders are committed by drug gangs, but that’s ignoring the majority of gun injuries are self inflicted.
And while it was written into the constitution it was amended into the constitution, and like the 21st which repealed the 18th, could be amended out again.
you also say there are 5x defensive Gun owners. This is a made up statistic - there is no formal definition of a defensive gun owner, there is no way to shoot a gun defensively.
While it may take time - a few generations - maybe even a dozen generations - to disarm the majority of households, it’s possible.
who are you disarming
the majority of gun owners own guns for fun/sport. So while, yes, it is sad to ruin fun, it’s also sad to have children killed.
Finally, you don’t have to ban all guns, you could keep say, bolt action rifles and single barrel shotguns - where sports and hunting could still continue. This wouldn’t solve all the problems but it might have saved lives multiplicatively in mass shootings.