>Also Tango was more AR than VR. I don't think they ever had any lead in VR.
They had inside out headsets before Oculus. Check out their partnership with Lenovo and the Mirage Solo headset. Despite working well for 6dof tracking it had the same terrible Daydream controller.
A year later Oculus released the quest with a better industrial design, camera array and 6dof controllers to much more success. The chip was a generation newer but arguably the success came from things that could have happened a year sooner.