I agree with you battery life is irrelevant. What is relevant is functionality and a secure phone and that means update, update, update. There are ways to mitigate daily battery life that is neither expensive or heavy.Like I have repeatedly stated, battery health is irrelevant if the device (iPads too) is on its original iOS version. Especially considering that OP has the iPhone with the largest battery ever!
We have two different interpretations of what OP asked for. Making a phone last four years is not the same as putting it in a time capsule. My sons XR and my xs max lasted four years both on ios 16.Like you said, functionality, app compatibility and support, and features are all significant drawbacks of staying behind, but like I said earlier, there is a very important fact:
-The only way to maintain perfect performance and battery life is by staying on the original version of iOS, or maybe the second major version like on the iPhone 6s. If OP wants that, they’ll have to adjust, like I adjust. That’s what they asked for, that’s what I gave them.
As far as I go, my anecdotal evidence, battery life is the same as on ios 15. We don't know if op is in the 1% of 1% where they will never upgrade their ios version. If the battery ages and interferes with the ability to use the phone, get the battery replaced. It's probably cheaper than getting your phone hacked.This may sometimes go directly against usability and always goes against features (like you stated and we agreed earlier), but there is no perfect solution as far as longevity goes. Battery life may not be the endgame for some, but it has been a factor in people upgrading their devices from the beginning. It reduces device longevity, unless the user doesn’t care (you are one example: you’ve stated that battery life isn’t as crucial for you as it is for me. You’ve also stated that you have no problem with carrying a battery pack). OP noted that iOS 16 has already worsened it, so I assume they do care. It’d be naive to think it won’t worsen further as iOS updates go by.
No, I want security and functionality.I’d be wrong if I were to say that there are no drawbacks, but my recommendation stands: do you want perfect performance and battery life?
As said in previous discussions, we hit that update button.Maintain the original iOS version and never update. Does it have significant and perhaps deal-breaking drawbacks? Sure! Is there another way? No. I wish there were.
This is not a true universal statement. Security and functionality are higher standards than battery life. Battery life is easily fixed, a hacked phone isn't.Tolerating or outright not caring about battery life and performance issues overshadows the advantages (maybe the user isn’t too demanding, maybe they’re light users so if updates halve battery life they don’t care, maybe they are okay with battery packs, and to top it off, maybe they do require updating), but not caring doesn’t mean the disadvantages don’t exist, it just means that they don’t matter to a specific user. In that case, it’s perfect!
So my xs max is in ios 16 and last me a day of my own usage. I get security, functionality and battery life. What's the issue?Again, as far as sheer device longevity is concerned, the only possible recommendation is never to update. Note that I did not say it was a perfect recommendation: it’s just the only possible (and imperfect) recommendation.
Making your phone last 4 years is different than preserving it in a time capsule. My xs max has lasted 4 years with a battery replacement. There is no stress in using it, nor do I care, if allegedly ios updates worsen battery life. Using a phone is not my raison d'etre. I got the phone to make my life easier not more difficult.(OP asked: “Any advice for making my phone last long enough until I can justify upgrading again, which is going to be a long time from now?”)