How To Remove Extra Space Around Text

The text top is not only the letters, it includes some margin, depending on the font size.

You can set a frame for the text, like here:

        HStack(alignment: .top) {
              Rectangle()
                .fill(.red)
                .frame(width: 15, height: 15)
                .padding(.leading, 3)
              Text("Heyasfd asdfsafds af awf s".uppercased())
                .frame(width: 200, height: 15)
                .foregroundColor(.black)
              Spacer()
            }

But that does not work if you need more height for text.

Or define proper alignment : https://www.hackingwithswift.com/books/ios-swiftui/alignment-and-alignment-guides

        HStack(alignment: .top) {
              Rectangle()
                .fill(.red)
                .frame(width: 15, height: 15)
                .padding(.leading, 3)
              Text("Heyasfd asdfsafds af awf s".uppercased())
                .alignmentGuide(.top) { _ in 5 }  // Moves up 5 points
                .foregroundColor(.black)
              Spacer()
            }