The Future of Cross Platform Frameworks

I don't see native development with iOS or Android using Swift or Kotlin really ever going away in the foreseeable future because it hasn't so far. Cross platform frameworks have been around since basically the beginning and they've never overtaken completely native development. If you're already building your web app using React, then by all means start by using React native. See if it meets your needs before you go through the trouble of building two separate mobile apps.