Ok so you want guns, kitchen knives, vehicles etc. to be illegal because we don’t know ahead of time if somebody will use it to harm somebody else? Very impractical.
Not what I said. I said Nukes. There is a huge difference. Nukes can only be used to blow up stuff. But the other things, while they can be used to do harm, their capacity to harm is orders of magnitude lower than the capacity of a Nuke, and, at the same time they have very practical uses that we depend on. So I can assume you will likely use a knife to cut bread or a gun in self defense, but I can't think of a common peaceful or legit use of Nuke.
So what you are really saying is that it comes down to a cost/benefit evaluation. You are OK with vehicles, alcohol, factories etc. harming and killing people as long as the perceived benefits to the public outweighs the cost. So nukes are not OK because clearly nobody benefits except the person who enjoys owning nukes, and the potential cost is high (millions dying when a nuke owner goes postal). The gun issue is really interesting. Obviously some people think that owning guns is worth sacrificing a few hundred school kids every year for. Others disagree. But almost everybody agrees that killing thousands of people every year using vehicles is unfortunate but acceptable. Perhaps you can argue that public roads and vehicles do benefit pretty much everybody. But guns only benefit people who likes guns and/or people who are more afraid of random violence than they are afraid of crazy people legally getting access to guns and shooting up schools.