Key reason for success for OnePlus had been price point. It's enormously popular in 3rd world because you can get specs that used to be 2X expensive from other. If you can keep quality same while reducing price by half, chances are that you are going to be very successful. Chinese company can do that but US company cannot because if they can then there will a Chinese company directly competing with them. Essential understood this and so never wanted to compete on price. You cannot win price war with Chinese company.