iPhone 7 Plus — The Case for 56mm
www.astramael.com/5
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
35mm is an established standard for general photography. It was natural for Apple to target roughly that focal length in 2007, but since then the iPhone camera has mostly featured even wider lenses.