Federated social networking solves this and didn't exist then. It allows separate networks to interoperate so you can still capture the overall utility of network effects. I think it would need governments to push this though e.g. recognise this as they might pollution and create the right economic dis/incentives.
If this was the standard model, you'd have greater utility as you wouldn't have siloed platforms and you'd get greater control over your personal data (as EU has already recognised and is legislating in any case).
If this was the standard model, you'd have greater utility as you wouldn't have siloed platforms and you'd get greater control over your personal data (as EU has already recognised and is legislating in any case).