Why is Text onTapGesture not working for widened frame in SwiftUI?

I have this testing file that is not working how I expect it to.

import SwiftUI

struct SwiftUIView: View {
    
    @State var boolTest = false
    
    var nums = ["1","2","3","4","5","6","7"]
    
    var body: some View {
        VStack {
            ForEach(nums, id: \.self) { num in
                Text("\(num)")
                    .frame(width: 400)
                    .font(.system(size: 70))
                    .foregroundColor(boolTest ? .red : .green)
                    .onTapGesture {
                        boolTest.toggle()
                    }
            }

        }
    }
}

struct SwiftUIView_Previews: PreviewProvider {
    static var previews: some View {
        SwiftUIView()
    }
}

When I tap on a number, the foreground color changes as expected. However, I want to be able to tap on the areas left and right of the Text("\(num)") so I expanded the frame modifier to test. However the color only changes when I tap directly on the number or text.

How do I tap on the space left or right of the number and have it change colors instead of it doing nothing?

The system treats the "invisible" (ie doesn't have visible drawn content) part of the view as unresponsive unless you set a contentShape on it.

//...
.frame(width: 400)
.contentShape(Rectangle())
//...