I'm both an iOS and web developer.
I fully understand what React (for the web) is trying to solve: UI's are hard and treating them as state machine makes it easier to keep the UI consist ant. The web version is also easily debuggable in the same tools you debug your regular JS code.
React Native is odd. It's not written in Swift/Obj-C and is not debuggable using the same tools we use XCode (and debugging is a big part of what we do to optimize mobile apps).
What are your thoughts?