The problem is, every companies claiming they are making a social network on top of blockchain, but most of them are making new proprietary cages for user’s data. Non of them implements an “open standard“ structure for recording users data by a safe and secure mechanism in a permission less blockchain. And non of them grant access to these data through API. All are trying to steal users (and user’s data) from other platforms to sell it to advertisers. So there will be hundreds of new social networks, like isolated islands with small population, which is another flaw of new SNs.
So no one can compete with Facebook.
If they implement an “neutral open standard” protocol - like what solid.mit.edu team are doing – and introduce it to world, so users can have “personal data sovereignty”, and companies could make their proprietary features for their customized social network.
In this case no one will compete on possessing user’s data. Instead the companies will compete on better services.