Can the Deck even drive VR graphics? It's a powerhouse at it's native 1280x900 resolution but it tends to struggle with the most graphically intensive games, much less VR.
VR has to render the game twice to give you depth perception, which is a big part of the increased resource requirements.
This isn't trying to do that, it's only displaying the game once. The effect of the glasses is supposed to be like having a TV a few feet in front of you.