It's my understanding that a lot of the appeal of RN is also that it allows web devs who are fluent in JS to make mobile apps, so I guess that's not really comparable in SwiftUI either.
I'm not sure about that. SwiftUI code looks an awful lot like React code. And IMO (as a web dev), it was always learning the UI framework that seemed like it would be the difficult part of learning iOS dev. Data manipulation APIs are pretty similar in most languages, but learning a new UI paradigm is a pain...