Ask HN: Between RN and flutter, is there a reason to choose one over the other?

I am trying to find a solution that will let us use the same code base on both Android and iOS. Initially, we were thinking about going with Kotlin for Android and develop an app with Swift for iOS later. But it would be nice to be able to launch on both platforms simultaneously. That's why we are looking at React Native and Flutter. So people who have experiences with both, is there any obvious reason to choose one over the other?