If you want the exact same app on both platforms, you can do that on React Native too. The Facebook apps don't do that because we believe it gives a worse user experience.
Ionic does not give you the exact same app on both platforms.
There are dozens of platform-specific styles in the CSS that make each target behave more like a native app. A custom-styled native app, but one that follows platform conventions.
I also absolutely abhor the fact that React mixes HTML with JavaScript. It just feels so completely wrong to me.
