More proof that most of those people have no clue about anything. Also, they’re probably not even using iPhones to begin with or not the latest ones, which complicates the matters even more.I have the iphone 13 pro max and also seeing the photo issue - first it's blurry then it takes about a second for the photo to become clear. I called Apple support, the rep reached out to their technician at the image or photo team for advise. First they said it was caused by my wifi speed and that the photo was taking time to upload to my icloud. I argued with apple support that it wasn't my wifi speed and they put me on with the senior technician who earlier suggested it was wifi speed issue. The technician ran some hardware test on my iphone and said everything (LiDAR, and other camera components) are working fine. I was asked to take the phone to a Apple Genius so they can "hold the phone and see the problem". I have appointment on Thursday so let's see what they say.
The delay in photo processing is normal: you can clearly see the algorithms and image processing doing their thing. I suggest turning on ProRaw on your phone and see if that helps. It tends to produce better and less harsh results overall. The Apple HEIF engine is just way too aggressive.