ContentView.swift

import SwiftUI

struct ContentView: View {
    var body: some View {
        NicerButton(action: {}, label: { isPressed in
            Text("Rabbit Season")
                .foregroundColor(Color.white)
                .frame(width: 200)
                .padding()
                .background(Color.blue.brightness(isPressed ? -0.3 : 0))
        })
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

NicerButton.Swift

import SwiftUI

private struct IsPressedPreferenceKey: PreferenceKey {
    static var defaultValue = false
    static func reduce(value: inout Bool, nextValue: () -> Bool) {
        value = value || nextValue()
    }
}

private struct NicerButtonStyle: ButtonStyle {
    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .preference(key: IsPressedPreferenceKey.self, value: configuration.isPressed)
    }
}

public struct NicerButton<Label>: View where Label: View {

    private let action: () -> Void
    private let labelBuilder: (_ isPressed: Bool) -> Label

    @State private var isPressed: Bool = false

    public init(action: @escaping () -> Void, @ViewBuilder label labelBuilder: @escaping (_ isPressed: Bool) -> Label) {
        self.action = action
        self.labelBuilder = labelBuilder
    }

    public var body: some View {
        Button(action: action) {
            labelBuilder(isPressed)
        }
        .buttonStyle(NicerButtonStyle())
        .onPreferenceChange(IsPressedPreferenceKey.self) { isPressed in
            self.isPressed = isPressed
        }
    }
}