But what is the one thing if you're just adding a dependency, where you're only adding it so that you can subsequently add a feature using it in a separate PR? The atomic action is adding the feature which requires the new dependency. Unless I misunderstood what you wrote.
I still agree with the original comment in that diffing technology feels decades behind, and that a lot of what we do as software engineers are working around things the tooling should be doing better on.
Sorry, I don't think I explained myself well. Generally when you see a lot of package* noise, it's because you've upgraded your dependencies, added one and made a feature change all at once. The main thing that needs to be separated is the upgrading part.
It seems no different than adding a feature dark in one PR and turning it on in a second. “The atomic action is launching the new feature to users” seems like an equivalent argument (and one with which I disagree).