The variable aperture is not for photos, it's for video.
I think people are framing this too much as a photography feature when it’s really more useful for video. On a sensor this small, variable aperture isn’t going to meaningfully change depth of field the way people expect. But it does give you control over light, which is huge for maintaining a proper shutter angle in bright conditions.
If Apple is serious about pushing iPhone as a filmmaking tool with ProRes and Log, this makes a lot of sense. It means you can shoot in daylight without blowing out highlights or cranking shutter speed and ruining motion blur, all without needing ND filters.
It might have some minor benefits for photos, but this feels much more like part of Apple’s push into pro video than anything else.
I, for one, can't wait to not need accessories to film on the go without the need for additional tools.