Camera+ (from Tap Tap Tap version 8.02 is latest and my mainly used camera app) doesn't take raw pictures it takes TIFF with stripped EXIF data but it is great for JPEG as you can get full size with no compression or jpeg 95 if you like.
Either way your post is first one that states not even raw does away with it when another user posted his raw file which clearly shows the detail lost from over compression and over sharpening on the jpegs which based on posts here lead one to belief its the algorithm used in Apple stock camera app not the photo app.
Others mentioned why reviewers didn't mention it and highly touted ones like the photographic standard DXO... the answer is not everyone is afflicted with it as they put the camera portion of phone through the wringer.
The other poster with the Forbes link is a rehash on AppleInsider story by their "Photo Expert" and shows examples of shots that show the Google Pixel with either the lens flare approx 1/2" from tree on left in sky or the effect one gets from too much saturation in sky.
I don't think you would find and engineer that would say any example shown is anything but over use of sharpening and noise reduction.... adding sharpening to jpegs is wrong.
Just another users 2 cents as issues with these expensive phones are no fun. Good luck to all. I would guess Apple once this is actually documented via Genius Bar visits and contacting AppleCare along with opening SPAC cases.