Ok, two things.
plenty of people on here explain these use calibrated screens etc. this isn’t a preference for blue white. It’s people not wanting their phone to look like it’s lit by candlelight. Because their PC, last phone, iPad etc all look white and this looks yellow.
my opinion. There were issues with some early panels. I’m on my 3rd phone and this one is only yellow with True Tone on. The other two were mild yellow with True Tone off. And they were less bright than my iPhone X. That was a hardware issue.
now I have a phone that is bright and white with True Tone off. But very yellow with True Tone on.
that could be IMO 1) faulty True Tone sensor 2) software issue.
given they have True Tone right on my iPad and X, I’m surprised they would get this wrong in software on the 12, and it would be easy to fix. So I’m guessing sensor just on that logic.
they can’t do a software fix globally if they don’t know which sensors are affected or they will have a bunch of users suddenly with a cold looking display.