What really, do you want out of a new phone?
Assuming you’re starting with a good foundation, I think the list of what really makes a big difference in phone upgrades is actually short. The first thing on the list is improved battery life. The second is an improved camera.
Those are the two things that make a fundamental difference in your day-to-day experience of a smartphone (assuming, again, that the basics don’t stink). Those are also exactly the things Apple tried to make better in the iPhone 13 and 13 Mini.