I don't know anything about Google Pixel and Xiaomi. But I have two phones that were discussed in this article: Samsung Galaxy S23 Ultra and iPhone 15 Pro Max.
I can say with confidence that the camera set in the Galaxy S23 Ultra is not for taking beautiful photos. I don't like these cameras at all. The photos are over-processed and look as if the contrast has been increased to an unnatural level. I didn't expect this from Samsung!
This camera is good for copying detailed maps or pages full of small text. But the photographs are not particularly attractive. Moreover, the cameras in previous Samsung models were better.
But the iPhone 15 Pro Max made me very happy! He has a great set of cameras and the photos come out amazing! The best device, in my opinion.