What is not clear from the description is how much processing of the image is carried out. For the iPhone that is a lot, taking most of the processing necessary for Mocap away from the CPU.
With a new device like the Vivo it also a matter of how much market share they have to see if it is worthwhile for RL to invest in development.
Lastly, the prices I saw for the Vivo are not much different from what you would pay for an iPhone XR, which is a proven solution currently. I'm not an Apple fan, but one has to be practical.