Flutter is better than React Native in all the ways that don’t matter

Perhaps If you are building a app optimizing for high performance where it is needed (using 3D, trading apps, etc) sure. But in 'all' cases? You would benefit better with the large ecosystem of officially 'supported' TypeScript libraries available in React Native which most companies simply would just use over unofficial ones or the very high likelihood of no equivalent libraries to use on the Flutter side, even if you are migrating a complex app.

Flutter is getting there but as for the library ecosystem, it's not there yet for now; especially for Desktop. If it does get there, at least we should be able to see the first of Flutter desktop apps like Rows [0] to replace Electron on the desktop, unless somehow React Native for Desktop gets there which that is even far behind.

[0] https://rows.com/

Any guy with reasonable coding experience in frontend or backend can do a project in React Native in less than one month. I was CSS/HTML frontend development back in the days and it took me one month to learn JS+React Native. It's very convinient and straightfoward process. In Flutter, with all the widget, folders, environment/IDE setup, concepts. It takes longer.

You will spend year teaching someone then he leaves for another company who gave him 20% rase. You're net negative, they're net positive. You'll lose the race in the end.

This could be a good approach for someone huge like Google or government. Asking that from an ordinary company will not work.

I want to throw Ionic and Capacitor (or any other webview based toolkit with your favourite SPA framework) into this mix, I believe for a lot of apps its probably a better option than either Flutter or React Native. I also don't and believe in "one true cross platform toolkit", each has its place. So:

Hiring - The OP suggests React Native has a larger pool of developers than Flutter, very true. But Ionic/Capacitor/etc you have access to an even larger pool of developers, any proficient font end web developer.

Sharing Code, Knowledge, and Developers - Again I believe Ionic/Capacitor/etc are even better than React Native here, you can potentially reuse even more of your code/views/logic. In fact your SPA web app version is your mobile app, except you then have access to native apis with Capacitor.

Developer Experience - Dev experience with Ionic/Capacitor/etc is as good a React Native at this point. It has all the hot reload features we now expect from any SPA framework. You can even now you Vite for super speedy development.

Performance - A webview based app on hardware less than five years old is on par with any React native app. The performance of web views is not the issue, it's the underling app code, modern SPA frameworks and good engineering is all you need.

Unified UI Experience - Firstly customers don't really care about a unified UI, they have been trained after 20 years of using web apps not to care. If it works it works. Having said that Ionic have done an incredible job of replicating the Material/iOS components.

Native Integrations - Capacitor has all your usual apis covered, if you need more it's as simple as with React Native to drop down to native with Swift or Kotlin. I'm a fan of using NativeScript with Capacitor, it gives you access to all native apis straight from your JS codebase.

Internationalization - Standard SPA internationalization support, easy.

Built-In Navigation - Use whatever your SPA framework uses.

Web Support - Capacitor is the clear winner here as you have built a SPA.

Third-Party Libraries - You can use any web/javascript toolkit, along with any platform specific libraries for iOS or Android that you need.

Obviously its not the right platform for all use cases, but if you are just starting out small with a tiny team you only have to build your app once. 90% of your app is probably the front end, your don't want to be build that twice until you have the traction and teams to do it.

Isn't the corollary that there are other companies who train up people who you can hire for a 20% raise from them? Or even just give your existing staff a pay rise once they reach a more senior level?

If you can't afford to do that, then that's saying you can't afford to hire people who know a lot about the technology you're using, and then that's a whole different issue.