They say that literally every year and I never notice.
For example, this YouTube video from a quick YouTube search shows fairly insignificant differences between the iPhone 11 and 13 non-Pro models: https://www.youtube.com/watch?v=XjosGytrIJI
As an example, I looked at this low-light photo comparison of the basic 11 and the 13 pro max:
https://www.gsmarena.com/piccmp.php3?idType=5&idPhone1=11089...
Sometimes the later model's image looks a bit better, sometimes it's indistinguishable. Meanwhile the 13 pro max costs more than twice as much in my country.
I think often a single year's improvements are negligible but real, so any given two year's improvements are much more noticeable.
physical crash, not the kind that can be caught
I really wish they kept on offering a Mini. Maybe I'll just go for a 13 mini, but the camera does look substantially improved, and satellite communication would be very nice to have (I do lots of hiking away from cell reception).