Creating a Web/Ios/Android project

Hey r/softwaredevelopment 😀

Starting an app project which I in the future want to be accessible on the App Store/Google Play and on the web. I have read quite a bit on React Native and feel like that could be an option. However I am still under the impression that I should share the backend code for all platforms naturally, but that i should split the frontend codebase into web, and the other into mobile app (IOS, Android) and just copy and paste the frontend code back and forth with slight adjustments, seems simple enough?

Does someone have experience with this, or with newer technologies that make this a more viable approach?

Thank you in advance! 🙂