I’ve always lagged behind in the iPhone cycle. Until recently, I had an iPhone 6 — which I’d used for years. Because it was slowing up, I bought a used iPhone 7 Plus, largely because of its camera, and expect to run that for years. iPhones — like all smartphones — have reached the top part of the S curve, and we’re now at the point where improvements are incremental and relatively small.

So this advice from the NYT’s Brian X. Chen makes good sense:

Apple’s newest mobile operating system, iOS 13, will work only on iPhones from 2015 (the iPhone 6S) and later. So if you have an iPhone that is older than that, it is worth upgrading because once you can no longer update the operating system, some of your apps may stop working properly.

For those with younger iPhones, there are ways to get more mileage out of your current device. While the newest iPhones have superb battery life — several hours longer than the last generation — a fresh battery in your existing gadget costs only $50 to $70 and will greatly extend its life.

If you have the iPhone 6S from 2015 and the iPhone 7 from 2016, the iPhone 11s are speedier, with camera improvements and bigger displays. That makes an upgrade nice to have but not a must-have. But if you spent $1,000 on an iPhone X two years ago, then hold off. The iPhone 11s just aren’t enough of an innovation leap to warrant $700-plus on a new smartphone.

If you wait another year or two, you will most likely be rewarded with that jump forward. That might be an iPhone that works with fast 5G cellular networks, or a smartphone that can wirelessly charge an Apple Watch.

I don’t believe that stuff about charging the Watch, but otherwise this is spot on.