iPhone 11 Pro - camera shows more on screen than is captured

On iPhone 11 Pro, 1x lens holding the phone in landscape, the camera is seeing a full picture to fill the entire screen on the phone, but the default 4:3 aspect ratio crops it, the rest is 'greyed' out round the edges and lost when you take the photo.... but the camera is seeing it because it's on the screen.

selecting 16:9 ratio fills the screen but it's just doing a crop of the 4:3 image as an edit (zooms in), it is not showing the full available picture at 1x.

what's the point of this wonderful big screen and camera which only captures half the shot.

how do I capture the full landscape image available at 1x ?