I'm on an iPhone X, which is on its second Apple battery. Apple replaced its speaker during the battery change free of charge, because it was broken or something, and I feel no urge to upgrade.
I'll be getting the latest and greatest in a couple of years, but no rush. That thing works the way it should, incl. battery life.
You get a couple of years of security updates, and new software starts to use the newest features to the fullest in the meantime, so when you take the plunge, it's always a bigger, more worthy jump.
You can safely leave the device behind then, to use as an emergency phone, if the need arises.
So, 1-2 years is not that crucial, but after that you really start to feel the gap. Same for Macs.
I'll be getting the latest and greatest in a couple of years, but no rush. That thing works the way it should, incl. battery life.