[dmitshur]

A random recent example off the top of my head: view photos in AVIF format. It does work in Photos app, but not in Preview app nor in Messages app somehow. At least this the case on iOS 26 and so I suspect iPadOS 26 too. It works on macOS 26.

Edit: I realize that ordinary people might not yet care about exporting to AVIF, but they may receive such photos from other people.