iPhone 13 Pro Max screen brightness

If you want it to look less mellow / yellow go to Settings, Display & Brightness, turn off "true tone" and "night shift".

Personally I find true tone exactly what it says and easier on the eyes.

If you can't adjust it in Control Centre so that it hurts your eyes in the evening then have the phone looked at

This is my normal setting

So get it looked at by Genius Bar. It may not be as white as iphone 11 (I never owned one) but it should be bright enough to use in any situation including medium sunshine.

oh and ignore advertising claims about being better at everything than previous iphones. It still scratches and probably lets in water if you immerse it.

Did you noticed True Tone option and night shift as it may cause more yellowish but you can change that