I've had... let's see... six iPhones. 3GS, 5, 7, 9, 11, 13. I reliably skip a major revision. And I would skip more than one, except that my mother gets my last gen. So when her phone needs battery service after being 4 generations back, I shop for a new one. But this time, rather than get a new one, I paid Apple a hundred bucks each to refresh the batteries in my 13 and her 11.
The 13 is a damned good phone, and there is not a single thing I would upgrade. No compelling reason exists. Thinner? Who cares? I carried the brick in the 90s. I've toted around flip phones, blackberries, pagers... this 13 is pretty much perfect.
I'll give it up when I drive over it, or LTE becomes a thing of the past.
Side note: Apple tech cracked my screen separating the shell. For my $100 I got a screen refresh too. :)