React.js being superior/inferior to Vue.js or others isn't very relevant unless the gap is huge, which it's not.
The quality of the language and documentation has been superb, and I feel more confident in my code than I did with another project written with JS bindings.
[0] I suppose the argument can be made that web-view components could be recycled with minimal effort, but that sounds like it'd be a worse story for end-users more often than not.
We developped a native app that looks pretty much Instagram. It is written in Swift and Java due to reasons you can probably imagine.
React Native became handy when we wanted to add a payment flow that can have native like ux, remote updates (adding new offers, disabling some options due to sudden legal changes etc) and a shared codebase. React Native with Codepush was the perfect choice. It had native like performance, updates without involving app stores and most importantly ability to be maintained by our backend Node.js developers.
Was it worth the add the huge dependancy just for it? Arguably yes. Tooling is good, integrating it took only a day. App size didn't increase a lot. Our backend developers had the chance to use already established in-house utility libraries.
Our design was to implement a React hosting Activity, a Fragmentand and a UIViewController. No issues have yet be faced and it works like a charm (users have no idea those screen are backed a few lines of Coffeescript.
Do you absolutely need a native-feeling mobile app? React Native (and ultimately React) are worth your time and investment.
In Gitlab's case, Vue.js works well for them because their product is web-first and allows them to iterate quickly.
For the most part, I consider React Native separate from React entirely. I consider most startups to either be completely web or completely mobile, and to let questions in the former case be answered by validating and iterating on the product quickly with a web app.
Some other frameworks have bindings to React Native using it as a just the final "renderer". CycleJS has a React Native binding, though I'm not currently aware of how well it works yet. I'm not aware of Vue.JS bindings for React Native, but it may be possible.
There's certainly a question of whether or not you need "native" to begin with. Cordova doesn't always feel "native", but it is reliable and reliable can be all some apps/dev-teams need.