I don't view a single codebase as the goal necessarily. While I see the benefit to doing a WebView everywhere, I prefer the React Native approach: write once, run anywhere by using the underlying native components of each system. Because it has such a great unified API for building UI, React Native is a good abstraction to use the same code everywhere. But what draws me to it is the fact that it maps onto native elements.

That said, I'm sure there are good arguments for Capacitor!