The ~$350 billion that those extra shares would be worth don't matter?

FB marketplace has a billion monthly active users. That's more than Amazon and eBay combined. Anecdotally I know people who hated FB before it was cool that have returned because of Marketplace. The feed, Facebook video, birthdays, events and a host of other features are still significantly used.

VR is a rapidly growing narrow niche which Oculus is dominating. I am a Signal fan and I actively push my contacts to use it but I don't see it surpassing WhatsApp anytime soon.

Disliking FB/Meta ≠ FB/Meta being irrelevant. There are billions of users left to come online and odds are that Meta products will be amongst the first they use.