This segment of users is probably not what "Meta" is concerned with.
Mainly, I think this is a push from a company who's idea pool has desiccated.
What is the end goal to have people in a headset talking to each other? That will happen irregardless of whatever platform it exists on, and unless FB is giving away unlocked headsets perpetually, I don't think people will pick their "Metaverse" over any other.
They might have an edge if they started as a peripherals company.
Say what you like about metabook, but at least its currently optional on your phone/device. Google and the myriad of shitness that is the android OEM manufacturer security is hard to escape.
Sure, you can use custom roms, but you can do this with oculus as well.