I believe it’s the size. I don’t get it, but many of friends prefer smaller phones.
For something to listen to music, order a car, view maps, communicate or browse a web page it’s really perfect. Fits in a pocket and can be used with one hand.
A couple years ago they called large phones "phablets." We've lost that word now.
The correct term is tablone <grin>.
I loved my SE until I bricked it jumping in our local pool not feeling it was still in my pocket — one of the downsides not yet mentioned. I brought my previous Nexus 6 out of retirement since there aren't any phones, Android or iPhone, that is worth new pricing right now.
Plus, I demand a 3.5mm headphone jack — dropping that was the most annoying design choice I can remember in a long time, in any consumer device.
Grrr.