Forgot to call out Combine, another important piece of the picture.

https://developer.apple.com/videos/play/wwdc2019/722/ (Introducing Combine)

https://developer.apple.com/videos/play/wwdc2019/721/ (Combine in Practice)

Whether you have any business in the Apple ecosystem or not, I think you'll agree they made some good moves on several fronts this year.

And as is the case with most Apple announcements, there's a lot of comments here saying that they weren't the first, about how SwiftUI is actually based on something we unearthed from the Mesozoic. Well of course, but very few are actually comparing these similar technologies. I personally prefer SwiftUI+Combine's way of doing X, even if it's clearly not the first tech to do X.

For example, at first glance, Dart+Flutter code seems full of clutter, whereas SwiftUI's

    Thing {
        ForEach(model) { data in
            Child(from: data)
        }
    }
    .modifier(y)
    .animator(z)

feels a lot more readable, although I think I dislike the $binding syntax, and the gradual creep of other stuff that looks like "magic" until you look it up. I guess they had to trade the semicolons for something.