Companies may develop experiences analogous to a Second Life, or Roblox, or World of Warcraft, or any other popular MMO (made more immersive by the VR medium), but I doubt they will have any further reach than those. At least I don't know why they would, anyway. To be fair, those games are successful and make lots of money, but compared to Facebook's current business they are a niche concern. So their enthusiasm seems misplaced to me.
Plus, VRChat already exists.
VRChat has so many flaws that you can't make that argument. It needs competition, and badly.
Just offhand I can think of:
* Massive performance issues
* Controversial handling of 3rd party modifications (enforcement was stepped up only to put lipstick on the pig for their Series D, and MelonLoader itself puts faux security on its software in an attempt to make it look like it cares, by curbing obfuscation)
* Poor security (players have been able to legitimately fry the hardware of other players due to GPU exploits)
* Even years after launch, still basic usability issues like status being changed unexpectedly, causing privacy issues