Some control over the direction of the spec to avoid situations like taking years to rewrite a working shipped spec, removing controller support, removing haptics, adding unneeded APIs, focusing on Cardboard and 3DOF, removing or not supporting link traversal, fuzzing headset tracking data. Or to be able to get useful features such as access to the headset camera or a way to bind textures without giant framedrops
If there was to be a "standardized/decentralized" "metaverse", things would have to move much faster. Think of all the features a "metaverse" might want, and each item would have to go through spec gatekeepers that don't even use/develop VR