Here is why Virtual Reality head-mounted displays (HMDs) have a long way to go in many features

It is now obvious that, to meet user expectations, VR HMDs have a long way to go in many features including display quality, degree of freedom (DOF), and connectivity.
According to ABI Research, the majority of VR HMDs currently available in the market support only 1080/2K resolution displays; which need to be greatly improved to solve the screen door effect caused by low resolution displays.
One can also observe that, new tethered devices with 4K display such as Aukey Cortex and Pimax and the arrival of mobile headsets with 4K display are likely to drive the penetration of high resolution VR devices.