Guys, turn off auto brightness for a fair comparison. Strangely, the iPhone 12 pro screen doesn’t get as bright when auto brightness is on. I don’t see any effect on the iPhone 11 or X. Therefore, if your iPhone 12 pro has auto brightness on, it will appear darker and possibly more “yellow” at the same brightness setting as another iPhone.
I bought an iPhone 12 pro at launch and I was disappointed about the screen not being quite as crisp or bright as my iPhone 11. However when I turned off the auto brightness feature on both phones, the screen is much brighter than my iPhone 11, and subsequently the screen looks more crisp. It is not as blue as the iPhone 11, but rather more of a true white. I was going to return my iPhone 12 pro, but now I am actually happy with the screen.
Make sure both phones you are comparing has the auto brightness, True Tone, and night shift all turned OFF.