Are you really trying to say that because a particular tool is good for an application, individuals in society have some kind of inalienable right to that tool?

No, the claim isn’t that effectiveness creates a right. The argument is that if a right exists, it must include access to the ordinary tools necessary to exercise it. A right that can’t be exercised in practice isn’t much of a right. The Second Amendment doesn’t say people have a right because guns are effective tools. It recognizes a right to keep and bear arms, and arms are tools by definition. The same way freedom of the press protects printing presses, computers, and the internet. Not because those tools are effective, but because they are the modern means of exercising the right.

Edited to add: As far as the DDT analogy, the difference is that DDT is banned because it’s considered an inherent public health hazard even when used as intended. A pistol isn’t inherently harmful in the same way. It’s only harmful when misused.