Because it’s a mobile device and increasing the screen to bezel ratio is always an advantage. It will still have some bezel it will just be smaller on the top and bottom. I don’t see how this is and.
Because focusing on one thing (such as screen size) is ignoring (or being Ok with) any trade-offs (such as ability to unlock the phone when lying on a desk face-up 1 foot away like mine is now, or additional benefit of secureness of holding when working an iPhone one-handed when your thumb presses the phone into your palm for an even more secure hold vs. swiping your thumb and having a temporarily-looser grip). You can't have it all, as us oldsters over 30 say.