My point is that this usage you describe will strain any battery, even one on the most efficient iOS version, the original one, even with 100% battery health.There are some scenarios I can think of that will put strain on an older battery:
- gaming
- recoding a movie
- Foreground and background tasks, such as listening to music or youtube while surfing.
- doing any of the above in hostile climates: such as Phoenix Az.
As long as usage is efficient, reading some material from your device without using any signal, low brightness...yeah the battery should support you.
To maximize the length between battery charges of course. I don't need all those daft features chewing up battery power indiscriminately. In fact, probably most folk don't so it makes more sense for low power mode to be the default mode. Let those who need to use those edge case features disable it.and by doing that you're disabling features and lowering performance. what's the point buying an iphone if you are just going to leave it in low power mode 24/7? i get it if you've had the phone 4+ years and the battery was really bad and you couldn't or didn't want to replace the battery.