Earlier quoted context omitted.
Until you want to do something full screen, then it might be a glaring black rectangle on top of the screen. The way to do it properly is to hide the camera in the thin bezels or somewhere else (inside the LCD, are we there yet?). This is just a lazy solution that designers probably even thought seems iconic.
But if you hide it in a small bezel or behind the LCD you will get significantly worse camera quality.
I feel like the only one that's still amazed by tech sometimes. I still look at planes and feel amazed we puny humans did that. It's never good enough.