Batteries spend most of their time in a draw or bag, when you leave home they are in a pocket or backpack.
So for most of their time it is their cost, size, weight. Design is not relevant, most of the time, it is technology.
The Powercore II 10000 is not a technology advancement, it is bigger and heavier than the Powercore 10000. The Slim 5000 (I own) is smaller than the Powercore II 10000 and it charges in 3 hours. Why does the Powercore II 10000 need 4 hours?
Oh, and you want to be paid more for it. $33 for something bigger and heavier than the $20 (discounted) Powercore 10000.
I am looking forward to true technology innovation, not aesthetic cosmetic changes.