You're talking centuries to remove 300 million firearms through attrition. Meanwhile your new gun ban has precisely zero (maybe even a negative) impact on violent crime and might even spark a civil war.
Great plan! Sign me the fuck up!
I understand that you think you're trying to help, but you don't understand the culture of my country. Kindly step off.
The point is you have to start somewhere. Your example is akin to saying for example: Fuck, at this rate we wont have legit quantum computers for 200 years so whats the point in trying.
Most people are dug so deep on this issue on one side or the other so you will hardly ever convince anyone to change their mind I get it. But its still worth talking about imo