Why YSK: I’ve been seeing an increasing number of phone photos shared online in 9:16, 9:21 or similarly tall aspect ratios, often with parts of the subject cut off. I’ve asked a few people why they cropped their images that way, and none of them knew they were cropped.
Also, the digital zoom just crops as well, so take the shot and then crop it, rather than try to aim a tight zoom.
Also true, though phones with multiple cameras often combine the UI for that cropping with switching cameras rather than having an explicit control to select a camera.