I like how you label that Samsung phone like it's the only Android phone in the galaxy (pun intended).
The point is, 14 hours talk/240 standby is by no means at the upper-half of cell phone battery life standards. Plenty of devices do much better, many of them high performance devices with larger screens than an SE. The Xperia Compact X has had it's specs reduced a little this year for market differentiation, but if we go back a couple years to the
Sony Xperia Z3 Compact, for example. This phone was Sony's flagship device (at the time) in a smaller 4.6" size (kinda like the SE is a 6S in a 4" size) -- but the Sony gets
920 hours of standby time. This isn't a case of shortchanging performance to extend power. Even it's
bigger brother got 740 hours.
You seem to have blinders on to the sheer number of Android handsets and the different capabilities they have. All you see is that Samsung model you're supposed to hate because you're an iPhone user, and not all the LG, HTC, Motorola, Sony, BLU, etc devices out there, some with 3000+ mAh batteries that still manage to be very holdable.