I know with the 11 and 11 Pro the bezels were more noticeable on the 11 because of the use of LCD. Is no longer the case now with the 12 coming with the same OLED panel across the board?
Using math on the specs provided by Apple, the side bezels on the iPhone 12 series vary between 0.13-0.14". The mini and Pro have effectively the same bezel thickness. iPhone XS side bezels are 0.16-0.17" thick.