In general you’re correct. This time around though, I see compelling reasons to upgrade except for 2017 iPhone users, whether or not one’s current iPhone is working well:
First and foremost, screen size. If you notice the jump from 3.5” to 4” to 4.8”, there’s no denying that the iPhone Xr 6.1” is a massive improvement (not valid for Plus owners)
Secondly, the 2018 iPhones are beasts thanks to the A12 soc. the fluidity of gestures, app switching, face id, is hard to describe without experiencing it (not valid for A11 iPhones)
Faceid is better than touch id and you get used to it in no time. Not always better but certainly 80/20. Desk use is not better because of the angles (using laid flat) so I have a wireless charging dock that lays my iPhone at a 70 angle.
For older users or people who want to save/spare their eyesight, ZOOMED display is a godsend! All the plus iPhones have it but the X/XS don’t. The Xr has this option. It makes my previous iPhone 7 look like a tiny toy.
For $800 the iPhone Xr 128Gb has a similar price to the iPhone 7 128Gb, which used to cost $749 at launch.