I used to be a yearly upgrader too. I think my iPhone X and then 12 mini were my first multi-year phones. Currently have a 14 Pro right now. Other than the battery life starting to suffer a bit, it still works like a champ.

I think the only thing at the moment that can get me to upgrade is if the iPhone ever offers proper external display and stage manager support. I think I might even sell my MacBook then too and use my iPhone as my only device. I’d probably also get something like a NexDock to use it as a laptop as well. One device for everything is my digital dream, anyway.

I’d say keep your 15 Pro as long as you can. Next year, even the year after probably won’t be significant upgrades. Maybe change out your phone case (if you use one), customize it with a MagSafe wallet (or something else), rearrange your Home Screen, anything to keep it interesting and fresh. A slightly faster processor, maybe a better camera won’t really do anything for you at the software level. Arguably, USB-C is worth the upgrade for some people - I’d partially benefit from it, but I have so many other lightning accessories, in addition to my wife’s iPhone and accessories, I’d have to carry around two cables for a while anyway.

I tried going back to my old S7 for a week, mainly as an experiment. I just couldn’t get used to the smaller size again from the Ultra.