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.