PC Gamer
Valve had next-gen VR 'headsets ready three, four years ago and they were big, bulky devices' but went back to the drawing board after actually putting them on

Summary
The Steam Frame is here and it's one of the best VR headsets I've ever had attached to my face, just don't ask me about the price. But when we spoke to two of the people at Valve who helped create the device—Joy Lyons and Jeremy Selan—they told me the company actually had its new VR headsets ready years ago, but they made the tough decision to pull the plug…
Steam