I’ve only built some basic CRUD-type apps in SwiftUI, but I thought it was pretty nice. The APIs seem well thought-out, I needed less code than I would have to do the same thing in React, and the default styling looked quite professional.

Of course, the React ecosystem and community is enormous. I bet if I was building something complex, I would have gotten frustrated building it all from scratch in SwiftUI when I could just reach for a React component library.