That is reproducible with any iPhone. I went back when the iPhone 17 was released and got the exact same result. Only enabling Apple ProRAW in the Pro phones resolves it. I showed it to the Apple employee next to me the first time and they were just as puzzled.
It seems to help with clarity on small letters and the kind of background text you'll usually find in city pictures, which is what most people care about - but I find the results very poor, especially, as the author mentions, compared to older phones.