Your last paragraph is a bit inaccurate. The dependencies are needed by people developing WITH React Native as opposed to devDependencies (which are for people developing ON React Native). So whilst you will be using the complicated graph of dependencies at some point, that isn't the same as saying they'll be shipped to end users of the app.

The line between dependencies and devDependencies got blurry the second npm packages got used for more than just Node.js itself. What's really needed to remove the ambiguity is something like prodDependencies, which would be a subset of the current dependencies, but I don't know if it's really worth it.