Do you really think so? I have an impression that the market is kinda OK with short battery life. Otherwise there would be a trend in this way. Maybe after other specs reach their practical limits?
1: http://www.kimovil.com/en/where-to-buy-xiaomi-redmi-3s-3gb-3...
Now if you want 2 weeks of battery life on a pocket supercomputer, well, good luck with that.