The Practical Triggers for an iPhone Upgrade

Personally, it’s the RAM size and a new battery.

We will not focus on how Apple is gatekeeping features from older iPhones (e.g., charging limits).

I drive my 13 mini to-date, and what worries me the most is the 4GB RAM size. 4GB means that my phone can only keep the camera, the photo album, and a single messaging app in memory before randomly killing one when I open anything else.
This RAM powerclimb is even worse than I expected. I was speculating on whether their 17 pro lineup will keep 8GB of RAM or bump to 12GB - they bumped it. This means that they will be keeping 8GB across their standard and ’e’ lineups, while giving 4GB more for the pro lineup. iPhone 13/pro was 4/6GB, 14 was 6/6, 15 was 6/8, 16 was 8/8, now 17 is 8/12. Maybe 18 will be 12/12, and 19 will be 12/16; 20 (anniversary) with 16GB sounds about right.
The problem with RAM powerclimbing is more and more bloated apps. Apps will take advantage of the larger RAM spec to “achieve more”. And we will unfortunately once again need more RAM soon at this rate. I see very few apps that understands “less is more”.

The battery also degrades heavily. Apple is always stringent with their “all-day battery life”, aka you need to charge if you ever need to get through a more demanding day.
I am fine with a smaller battery, but the degradation of an aged battery is the second reason I want an upgrade / a battery replacement. With a new battery, you have the least electrical resistance in the battery cells, which means both more heat capacity for your chip and higher conducting efficiency to power your chip. As resistance climbs, the voltage takes a dip; and any higher current draw can dip the voltage further to a point that the chip needs to ease on the gas pedal. This is a common issue across all li-ion powered devices.

I think (cope) 4GB of RAM can still be usable for a while, but I might need at least a battery replacement soon.
If the RAM leeway can only last me another year or two, then maybe it’s just better cost performance-wise to upgrade; not essentially to the newest model - the 16e is very enticing given its 8GB RAM and a healthy amount of battery capacity.

The problem is they killed the mini series line up, and the prognosis is poor. I might just have to live with a 6+" brick soon.