Is it reasonable to use percentages with UIScreen Height?

Is it reasonable to use percentages with UIScreen Height to make auto layout in SwiftUi? I am quite new to Swift and I need to make an auto layout but as I know SwiftUI doesn’t have margins as UIKit. So I usually use height and width with percentages to make layout flexible for all iPhones. But I think that it is a bad option and hope that better ones exist.

Available from iOS 17

You can use containerRelativeFrame(_:alignment:) as such:

struct MyView: View {
    var body: some View {
        Rectangle()
            .containerRelativeFrame(.vertical) { height, _ in
                height * 0.35
            }
            .overlay {
                Text("Rectangle with height equal to 35% of its container")
                    .foregroundStyle(.black)
            }
    }
}

Before that (iOS 13+)

If you want to make your views size adapt to their container, you can use GeometryReader like this:

struct ContentView: View {
    var body: some View {
        GeometryReader { proxy in
            Rectangle()
                .overlay { 
                    Text("Rectangle with height equal to 35% of its container")
                        .foregroundStyle(.black)
                }
            .frame(height: proxy.size.height * 0.35)
        }
    }
}