Earlier quoted context omitted.
Letting it go down to 20% before charging it back up means the battery has to cycle, and as I understand, that's what "ages" it. And managing that is on you, it's not Apple's fault that you won't (or can't) plug it in. What can be Apple's fault is the battery going to 10% after using it for 3h, but I don't think that's the point here.
I'm sorry, but how can it be my fault for using a device until it's battery is low-ish? > Letting it go down to 20% before charging it back up means the battery has to cycle Apple actually says themselves, that "You complete one charge cycle when you’ve used (discharged) an amount that equals 100% of your battery’s capacity — but not necessarily all from one charge." [1] The iPhone 12 mini has a 2,227mAh battery. Its…
Whatever time it spends unplugged, is time spent draining the battery. Down to 90% or down to 0%, it's just a difference of amount.
If you keep it plugged most of the time, and only drain it to, say, 90% (and this is an arbitrary number), you only used 10% of one cycle. If you let it unplugged until it's down to 0%, you use 100% of one cycle.
If every day you let it go down to 0% and then charge it back up, in 10 days you've used 10 cycles.
If every day it only loses 10% (total) and charge it back up, in 10 days, you've used 1 cycle.
I'm not saying "it's your fault" or that "you shouldn't do it", I'm talking about objective use of the battery.
Yeah, I know it's a mobile phone, so one of the reasons for buying that is to use while out and about.
But the point is that not everyone uses it that way, which can explain why some people see the battery health going down faster than others, on the same device.
And that's not Apple's fault. Sure, you could argue that the battery life is ridiculously short, that the battery's health shouldn't degrade as fast, and so on. And I'd agree with that. But still, it's a different issue.