Do all oled iPhone have screen burn in?

Just wondering if the XS max oled would be more better than the x and before coming to iOS i used a galaxy note 8 without the knowledge of screen burn in for I do recalling used a bright screen and no caution at all but still phone got me through a year and was sold…., just feel not all units of either iPhone or Samsung using oled panels would have a burn in.., what do you think