How to change aspect ratio of screen

I am trying to change the aspect ratio of my phone's screen, presumably by changing the resolution, to achieve the result shown in the image. I am not trying to just change the resolution without changing the screen size as you would with an app such as 'nomone resolution changer' I am not trying to hide the top and bottom of the screen as you would with an app such as 'notch hider' I am not trying to just move the icons on screen as you would with 'adb overscan' I want the device to behave as if those areas of the screen are not there at all, so they just stay black all the time I know this will require root so bring on the root solutions Thanks in advance