I keep saying, the best way to play the iPhone upgrade game, is to wait it out. You can get a iPhone 7 Plus now for 650. Yeah, its a 2016 phone, but I still see people like my sibling rocking an iPhone 5s, which he just upgraded from an iPhone 5. I have the iPhone X, which I upgraded from a 6s (still have it).
Going forward though, my upgrades will slow down significantly. Seriously, I won’t be looking at another iPhone until 2020. The features are not ground breaking must haves anymore. The first iPhone was enticing, because it was genuinely a breakthrough with lots of flaws, if you waited a year or more, you got a better device.
We saw them each year: 3G network support and App Store (2008), Record video (2009) - although this should have been in both the first and second generation, FaceTime and Retina display (2010).
2011 things started in a new direction, where upgrading every year wasn’t a must have. Siri wasn’t all it was supposed to be, but Apple obviously was first and saw the signs. Eventually, Google and Amazon won that race with their digital assistants. 2012 introduced a 4 inch inch iPhone, but it wasn’t dramatically inspiring enough that you needed to upgrade.
2013’s iPhone 5s was substantial under the hood with the first 64 bit processor. This made it a must have upgrade because of boost in performance and future proofing. Look at the fact that it will get the iOS 12 upgrade. The 2014 6 pretty much saturated the market with good reason, larger screens across the board. This is what Apple should have probably delivered in 2013. But, that upgrade was a must have for many, even if you bought the 2013 iPhone.
After that, 2015, 2016, you can obviously see we are now on a status symbol journey with each iPhone upgrade. It’s not that 2007 feeling anymore. The fact that you could carry this device around in your pocket do email, read nytimes, listen music, watch videos, capture photos and do it so seamlessly and still send and receive calls. There was a hint of that feeling when the Apple Watch got cellular capabilities, but it was inevitable, but bubble kinda burst, since, you could do it over Bluetooth.
People will keep buying the iPhone, because, the ecosystem is great, but you don’t have to get the latest and greatest; and looking at Apples price points now, you should run your device until Apple stop supporting them with iOS updates. If you have the money though, there is no stopping you, so enjoy it - you earned it.