Sometimes I think the screen race is shooting the device in the foot. Anything after the retina display in the iphone was just diminishing returns. People aren't going to notice refresh rate or more pixels beyond what they can already resolve at that distance scrolling instagram, but it sure makes for great ad copy. I'm a bit of a radical where I think retina display is overkill on a laptop even, since I'm sitting here on my 1280x800 pixel laptop and I can't see any pixels from where the laptop actually sits in practice.
I've had an iPhone XS since it was released, it's only just barely starting to show its age, mostly with shorter battery life. Five years is a good long run for constantly-improving tech. Life is short, you simply won't have to worry about that many upgrades.