I don't think you understand what React Native is.
It's just a way to use the underlying native UI. It's not a bunch of emulated components with a pluggable "look and feel". They're the real thing, just wrapped in a JS API.
No, I understand it generates native components. But if you're writing generic UI code and deploying it on a Mac without following platform conventions (about the menus, ways of doing things, etc) it will still feel 'wrong'.
It's just a way to use the underlying native UI. It's not a bunch of emulated components with a pluggable "look and feel". They're the real thing, just wrapped in a JS API.