You are mixed up 3 different tech stacks:
1. React Native has nothing in common with web apps except JS runtime. It uses "native" widgets for Android and iOS. You need to add a new "native" runtime for your free OS. There are some third-party attempts to add mac/win/linux support, but they are not feature complete as officially supported platforms. Again, your free OS will be step behind.
2. Yes, you can write PWA with React (Web), but PWA still have many missing features which offered by platform APIs of Android and iOS. Your app will not be in "feature parity" with "native" app. Especially banking app.
3. Electron apps are integrated with desktop platform APIs, you cannot easily port Electron app to mobile.
Every time big company with big investments wins.