The package.json file hasn't been remotely close to representative of the actual dependency count of a JS project for years.
Plus I forgot to address this in my earlier comment: that visualizer only shows dependencies. By default it doesn't load any dev dependencies. You can confirm that for yourself by checking out https://npm.anvaka.com/#/view/2d/rollup for example - only the single runtime dependency on fsevents shows up, the dozens of dev dependencies Rollup has don't.
So yes, React Native does ship that overcomplicated graph of dependencies to all its users. I'll grant that at least _some_ of the code in those dependencies gets tree-shaken out.
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.