1. Cheaper iPhone
2. You don’t want to carry a big iPhone and you have a Mac/iPad nearby anyway for anything complicated so a big phone is unnecessary.
The second case should motivate wanting eg their ‘pro’ cameras in the small phone but the first case motivates making it cheap and low-margin. You can also imagine a world where apple markets a mini phone as also being an optional companion to a bigger phone, but they already have the watch for that.
Wasn't the 11 pro the size of the mini / SE? I don't remember whether there was an 11 mini, but it seems to me that 11 pro / SE were exactly that, and the current minis / se are the size of the 7/8/se/11 pro.
I the time I couldn't justify buying a new phone, but I remember late last year, when I figured I could start looking, I was possibly contemplating getting the 13 pro, for the camera. But when I saw how huge it was, I immediately abandoned the idea.
The iphone 12 mini and 13 mini are both smaller than the 2nd/3rd gen SE but larger than the 1st gen SE.
The 2nd/3rd gen SE is the same size as the iphone 8.
> 2. You don’t want to carry a big iPhone
If you add those two up, you get "Middle school kids".
Though the apple watch with its own SIM has solved some of the "contact device without instagram" needs that parents want with their kids.