The main benefits for us come down to the fact that we have a large existing JS web application that would take a lot of energy to port to both native platforms (we know from experience, we tried it before). Using React Native, we can share a significant amount of the data and controller layers between web and native. This also means that when a feature gets written for the web, most of the work is already done on mobile (if it was written correctly).
The other key difference is the sheer numbers of each different type of devs we have. At work we have ~400 JS devs and ~30 each of iOS and Android devs. It's just not reasonable to expect the native engineers to be able to keep up. Exploring React Native lets us distribute the load of app development off of the native engineers and put it into some of the web developers. Arguably, an alternate solution would have been to just hire more native devs and I gave that suggestion to management, but that wasn't the direction they wanted to take.