Nobody bought an iPhone or iPad because of Facebook. You could also install the Facebook app on that, but you could also use your notebook or your desktop pc or your cheap Android phone or whatnot to use Facebook. Most people already had some "Facebook ready" device at home.
Nobody will buy an Oculus headset if its main/sole use is the Metaverse.
Zuck is betting that more people will use VR in the future, and if you believe that hypothesis then it makes sense to invest infinite money in making sure your company becomes the Apple of VR instead of the Nokia.
How wisely that infinite VR money is being spent is another matter.
We'll come back in a few years or decades time to see who will transform the glasses into another platform, just like the watch and the phone did.
Meta just needs a killer feature for the Metaverse. During the pandemic they bet hard on office-by-VR, but they moved too slowly missed the pandemic and many other deadlines before making a good product.