Another great option seems to be Flutter web. I was really impressed by the "batteries included" approach to Flutter, and Dart has a pretty comprehensive standard library. This is in contrast to React's "just find a random package on npm and pray it doesn't bite you in the future."
Obviously rewrites are expensive, but I personally think both approaches are worth considering versus abandoning native components completely. WebView isn't without problems (and also, you don't need React Native to use WebView).