It's quite unreal that people are blaming the users for taking bad photos when this is clearly an issue with the phones (possibly a software issue).
Both my iPhone 8 and my wife's iPhone XR went from being very capable cameras to produce worse pictures than my old iPhone SE. Am I better at taking photos with the old phone? Did I suddenly become a worse photographer after one of the iOS 13 updates? I can still shoot superb photos with my Canon 5D Mark IV and Sony A7M3. The only variable is iOS updates.
I've compared the EXIF between multiple photos shot with the iPhone XR, before and after iOS 13, under virtually identical situation, this is the trend.
Before (iOS 12)
Today (iOS 13.2.3)
So before, the shutter was fast, resulting in non-shaky looking images and still subjects, and the incredibly low ISO returns clear , non-grainy images. Again, under the same condition, the shutter is going down by a lot and the ISO is being raised.
With proper IOS, shooting at 1/40 should be fine with if the subject is still and on modern DSLR you can blow up the ISO up to the 3,200 range (a lot higher on higher end models) before you can see any grain. Comparing DSLR and Phone camera sensors doesn't make a lot of sense, but since the main commenters defending Apple see themselves as professional photographers and think everyone else is doing it wrong, I felt like leveling the playing field.
Stop blaming the users, there is something wrong with the camera, the camera's api or something - but it's not the user as multiple users are experiencing the same issue.