Yesterday I went shopping in different malls and visited various local stores selling Apple products. I took the time to compare my 13 PM with others 13 Pro or Pro Max in the displays and the inconsistencies were more than obvious. No screen was exactly the same as the others. Some were warmer than mine, others with a nice white temp but looked washout, and one of them was really reddish to the right side, just like a 45 degrees gradient from left bottom to the top right. I talked to one of the managers or supervisors and they are aware of the situation and according to this guy, it always happens since the introduction of OLED panels. For him, the worst time was the 12 series. He removed the reddish iPhone 13 pro from the display after I show him how bad it looked. He said the big majority of people don't care or can't notice this issue. Only tech professionals, photographers, and others alike are sensitive to these kinds of problems and end replacing their phones. He always recommends returning the device and exchanging it for a new one o get your money back and wait 5 or 6 months until the manufacturers sort these issues out.
I’ve been to a couple of Apple stores now, and I think you nailed it. Even if mine was better in some regards, it was different/worse in others. There is a lot of variation in temperature, tinting, and brightness. Looking at all the different displays almost left me more confused about what good would look like, except for the really obviously bad ones.