I’m sure that Apple did tons of A/B testing, focus groups etc. with different image processing parameters to arrive at the settings that their phones use for photos, and from these comments it’s clear that a lot of people prefer the iPhone photos. When I was in grad school (in the pre-iPhone era) I photographed lots of weddings on the weekends, and one thing I noticed during the process was that people often have a set idea of what good photos look like. This idea of a “good” photo is often not tied to what the scene in front of them looks like. For example a “good” photo that includes a sunset will show a highly saturated orange/red sky, even if that’s not what the sky looks like at the moment the photo is taken.

Personally, I carry around a Ricoh GR3, and shoot random shots with the iPhone, but when it really matters I’ll use the Ricoh. The way the iPhone flattens the lighting is what bugs me the most. Recently I was at a kid’s birthday party and each kid had a cupcake with a candle in it. The room was a bit dark, and the Ricoh photo showed that each kids face was illuminated just a bit by the candle in their cupcake… The color temperature of the candle light is warmer than that of the room light. The photo makes you feel like you’re really there. My friend shot a photo on her iPhone at the same time and we compared afterwards. In her photo, every kid’s face is well lit and the candle effect is gone. She likes her shot better and I like mine. Some people want a shot that reflects what they saw, and some people want a shot that looks like what they think good photos look like.

MKBHD does a phone camera tournament (yearly?) and I believe at least once he found that people prefer a brighter image, even if that didn't match reality. No source or proof, just something I vaguely remember

I have found that non-photographer people have generally have absolutely no sense of what makes a good photo. They don't care about composition, lighting, colours, detail, or ambience. Their mental/emotional impression of what the photo represents is more important than the photo itself