React Native or something like it is almost definitely the future. It's totally unreasonable to write two totally separate copies of your app using languages that take a while to build and compile.
React Native basically solves this and solves it well, and can perform well in most cases.
And if there is some screen where it doesn't (ex. if you were building Snapchat and were going to work on live video filters), you can implement that in Swift/Java/Obj-C and just make that a native module that's part of your RN app.
My personal prediction is that almost all apps will be started in RN in the medium term future and most will end up mostly RN.
If the js ecosystem taught us something is that react and his derivates are going to fall and being replaced by another iteration of new tools very shortly, and then repeat.
Honestly I think in 1-2 years at max reactnative will have the same popularity of Ionic and Phonegap at max, and probably far less if react will fall against the newcomers of the web-frontend space (vue.js, inferno.js, riot.js, etc) as fast as it seems doing right now, remembering closely the time of angular1 eof vs react beginnings.
React Native basically solves this and solves it well, and can perform well in most cases.
And if there is some screen where it doesn't (ex. if you were building Snapchat and were going to work on live video filters), you can implement that in Swift/Java/Obj-C and just make that a native module that's part of your RN app.
My personal prediction is that almost all apps will be started in RN in the medium term future and most will end up mostly RN.