There's one thing everyone really wants from their smartphones
The modern smartphone is perpetually improving. Chipsets get faster, cameras get stronger, displays get sharper, software gets refined. In many cases, these things have advanced to the point where you can get something totally decent for $50.
The one resource there'll never be enough of, though, is battery life. And as this chart from Statista shows, that's all anyone wants. According to a recent YouGov survey, longer battery life was easily the most desired feature for US smartphone users. Things like water resistance and shatterproof screens are wanted, too, but got less than half as much interest.
At a time when more and more manufacturers are hoping to stand out with very thin phones - which naturally leave less room to fit a battery - this is significant. At least in this case, those device makers might want to trade some form for a little more function.