The reason might be linked to the evolution of smartphone technology. As the capabilities and functions of a smartphone began to increase, it also lead to the faster use of the available battery charge. All too soon battery life became an important parameter when buying smartphones. So the solution for it was to put bigger batteries into the phones. But then came the next problem, people prefer thinner and lighter phones. A bigger battery won't help with any of these issues. The solution to this was to charge the battery faster. It was Qualcomm who came up with a way to charge the battery faster.