Yeah, but since we pay for our phones through our 2 year contract, we just upgrade when it's time to avoid paying even more for an older phone.
She uses Facetime and social media a lot so the bump in camera has been noticeable for her, especially the front-facing camera. And the battery life was an issue late in to her 6's life. Sprint has upgraded radios in the 7, too. Carrier Aggregation, I think it's called? So she gets solid LTE speeds in our house, and on the go.
She really just cared about the battery life and camera part. Also, her 6 was a 16 GB model, so now that Apple has a base 32 GB model, it meant she wasn't constantly deleting apps and reinstalling them to clear her cache. That's still such a huge flaw in iOS, that that information isn't easily accessed by user and able to be cleared.
Yeah, I have the iPad Air (which I also think was the best iPad) and I have just 3 or 4 apps installed on it since I use it just for web browsing, and over the years its available storage shrunk to 2gb. I will have to do factory reset soon just to fix that. I suspect one of the reasons is garbage the current apps generate and keep, and the other issue is not being able to clear after uninstalled apps. On Android I can just completely delete old app's folder. There were so many cases where a game would download additional data and uninstalling it would just remove the app, but not additional data. I know for sure I had that when I tried Mortal Kombat X back in the days on the iPad, it would download like 2gb or so additional data and I haven't seen it back since I uninstalled it maybe a year ago.
Also it's funny how people these days upgrade their phones because of such minor changes. Everything you mentioned would be fixed by a new battery (the old one surely wore out after 2 years) and getting a new SD card for like 20$ to have even more storage. It's ridiculous how things changed to the point that people find it fine that Apple is preventing such DIY upgrades and forces you to buy a completely new phone instead.
It sucks it's also starting to affect Android manufacturers too. Glad Samsung reverted from no SD in the S6 to S7 with SD support - Got a 128gb card for like 40$ and it's all set. But still, almost everyone seals batteries these days, and those batteries simply don't last and after 2 years you're forced to trash your old phone, which is super shitty, as in the past I would always sell or give away mine that could still work and make someone else happy. Now it becomes polluting garbage, even though the most critical parts of it are completely fine and would be for a very long time. Sealing a battery basically makes your phone go from a device with potential to last years to a disposable one with a 2 year life span for the whole device generation.
Kind of like with cameras - people can still use a 80s or 90s camera, you just throw in a new battery and embrace nostalgia overload. People upgraded because new generations added value for real, and it wasn't every year or two, while the markets on electronics were doing fine and there was more progress.
It's sad that technology moved the way it did, and that all of today's devices die without a chance of ever being used in the future more distant than 2 or 3 years. We upgrade because we have to, to devices capable of doing the same as the previous ones that we were pressured to upgrade from.
The amount of processing power and functional technology we trash due to serviceable parts wearing off these days is sad.
It's kind of like trashing your car and getting a new one because it ran out of gas and there's a new model with a full tank and new rims, and you can't refill the tank.