alt Hacker NewsIt is virtual dom like. We don't have access to a stable underlying element like we would with plain UIKit. You can build declarative models without this virtualdomness. But SwiftUI was created during the react boom so they went with the Zeitgeist, understandably.
Now this is somewhat problematic if someone wants to implement better fine grained reactive systems. And I posit that the next paradigm is going to be in that direction given what I've been working on (furthering current reactive systems which only go halfway).
This is such a clueless take, and I see it surprisingly often. Declarative UI does not inherently mean virtual DOM nor does it "automatically" mean slower than UIKit.
The abstraction is huge advantage, especially when targeting different devices and screen sizes. We (and that includes Apple) have been learning the value of those kinds of abstraction boundaries for years, well before React.
It's also important to note that SwiftUI and UIKit are composable, so if some small part of your app needs low-level, finer grained control, then go ahead and use UIKit/Core Animation/Metal and SwiftUI for the rest.