I agree with most of what's said but wanted to check a few facts?
If you do want a phone that you can upgrade to extends it's life there is a good company called fairphone which allows a degree of upgrade per device/frame.
https://shop.fairphone.com/fairphone-5. I am not certain it works out cheaper than a couple of -1 or -2 gen phones but it does allow you to make a gesture.
Yes it is the cutting edge of fashion devices in the technology industry and we are seeing minor incremental improvements per generation now with a lot more marketing. We had the years of better and better screens culminating in a pretty small size with more dots than your UHD TV. Nuts. We have had the years of my camera's better than yours, I have to work hard to find the difference in most normal point and snap moments.
Nearly every carrier now tries to implement re-cycle programs and advertising for them is all over the place. CEX (webuy.com) always has a good range and offers A, B and C grade finish with cost savings. I use them for demo devices and they are consistently reliable, more so than eBay. Newer to older devices go to different places. The smartphone is making a great change in Africa and enabling real advances in peoples lives by underpinning finance security.
There is still a big problem with companies that provide smart devices and then rotate them at two or three year cycles. Competition between the carriers also stimulates this. It is a perk that people like but given most devices get software updates for 4-5 years it is not really good but we are seeing changes in this space. Apple is better for extending the life through updates, Samsung is close, others vary a lot more, you may get less years.
Older hardware will lock on a software version at some point. This does not stop it working but it has two main issues? Some apps will only work on new(ish) versions of software as they want to leverage the latest security features. Banking, software key for cars etc so if you live on these then it should mean time for change. The other is that you will not get security updates (mostly for the new buggy features to be fair!) so it does increase the risk of personal data compromise. If you don't keep critical stuff on it then older boxes work well.
So which device would I choose. If we say a device has a five-six year life getting updates and this is important to protect your identity then you should work out how much you want to spend. If migrating phones is a pain you don't like get a renewed -1 generation (iPhone 13 right now) and get 3-4 years of peace and security. Same for Samsung. Some of the other vendors depreciate a lot quicker so you can get a newer version for the same price but they may not get updates for so long.
I would like to balance a few things.
Most mobile devices use processer chips based on ARM, a wonderful British company. Recently the various vendors of these started to integrate them into chiplets with more functions to make them faster at lower power. With each generation Apple puts on one more fast or eco CPU to get better numbers. The computer will only use power when doing stuff. Its more often the Apps and other connections that result in battery life issues. There is constant pressure on the operating system (iOS and Droid) to open up the OS to do more things which suck more power. It's the current "mines bigger" area, we probably have more power than we need for 99% of people now. Great for apps but as a vendor you then get a reputation for poor battery life. For Apple they own the hardware and software so they have tighter control. For Android+Vendor it takes a little more work and often is not quite so efficient, maybe 5-10%?
The additional speed of 5G is actually a good thing in some ways. If you have a file to transfer (photo) it runs faster to download then goes to sleep so the power consumption can be less. Same with the CPU, it can do work and go back to sleep. I would not put the blame at the hands of the
Chatty apps like sochel medier are constantly running in the background to update and drag your attention to them. News apps compete to update and badge, how many messenger apps do we need? Many more applications now carry almost no content on the device and stream it on demand resulting in greater demand on the comms engine. People stream a youtube video in FHD 1920/1080 to a 4 inch screen without a thought. Software has a default setting of "highest available" as they all want to wow you. Inspect the settings, change the notifications levels to shut down less important software. There are a lot of settings you can adjust to improve things without impacting most of your experience.
The re-organisation of the spectrum is a good thing. It is the same as closing off the OLD analogue TV bands, pulling back the spare spectrum and reusing it for a massive increase in capability. One old TV channel became a LOT of new other channels. Where else are they going to get the new channels for 6G in order to sell the iPhone 18, ahem.
If you think how much engineering is packed into the tiny package and how long it does work for it remains amazing to me how they put so much capability in it. No item in my 60 years has had such a critical part to play in (perhaps younger) peoples lives? It has become a dominant thing.
