I’m a react native and flutter dev. They’re very, very good for 90% of use cases. Even if you’re only developing for one platform, they’re actually quicker to get started on and be productive than native development, especially if you use something like Expo to get your app started as fast as possible. If you’re doing performance critical applications or need access to hardware other than the usual camera/Bluetooth/internet, then you probably are better off writing it natively but that describes a very small handful of real-world apps and you can always selectively write some parts in native code.

EDIT: Also I didn’t think it had to be said cause I thought Xamarin was basically dead but yeah, Xamarin sucks major ass.