How to properly animate a Slider in SwiftUI?

Question

I want to animate a Slider whenever its value changes with a custom animation (with a custom duration). But somehow it doesn't work. No matter what animation I specify, it always uses the same (very short) animation that is almost not noticeable.

Here's a minimal code example:

struct SliderView: View {
    @State var value: Float = 0

    var body: some View {
        VStack {
            Slider(value: $value)
                .animation(.linear(duration: 3), value: value) // ← here 
            Button("Toggle") {
                value = value < 0.5 ? 1 : 0
            }
        }
        .frame(width: 300, height: 200)
        .padding(16)
    }
}

What am I doing wrong?

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Note 1: Without the animation modifier, I get no animation at all and the knob immediately jumps to its new position. With the modifier, it animates but it doesn't seem to respect the concrete animation I specify.

Note 2: I know that I could use an explicit animation and wrap the change in a withAnimation closure. But even if that worked, it's not an option for me because the in my concrete case, the value is not a @State but a @Binding and is thus set externally from a view model that should not know anything about SwiftUI.