Exactly, well put. A non profit distributed MR metaverse would actually be pretty cool, eventually involving the use of some sophisticated glasses through which we would still see the real world, but in which we would see digital artifacts from a parallel digital twin of the real world, which would mean we go back to real world socialising whilst staying connected to the virtual world. So those glasses would have the opposite effect from conventional screens; they would actually make us more physically social. Further, they would probably become designer items, quickly replacing mobile phones.
If it is any consolation, it isn't even possible to do as anything but a non-profit, its success requires implementation of a common virtual digital twin of the real world which would require to be fully distributed just to have the data storage capability.
As we can see it wasn't even possible to unite the world to create a common covid vaccine, and we are now struggling to present a united response to climate change, the chances of creating the required digital twin as a profit seeking venture are zero.
The only way facebook might conceivably have a chance of doing it is if it somehow became publicly owned.
I don't see much chances of that, unless by some fluke, the effort of embarking on it ended up with fb somehow being sucked into the non profit world.

Not impossible, if they were also to pursue becoming solar powered, as that ends up with free money for all users, including the organisation itself, from solar powered proof of work tokens like Bitcoin.

Ironically, that would also solve the climate problem, and because of the collabarative nature of it, common vaccines, free for all, would also quickly become possible.