Unfortunately, in my opinion, Facebook is here to stay.
Reasons:
- Local/OSS/decentralized social networks will not work for the common population because their friends and updates will not be there.
- Video based is already a success, see Twitch, but people sometimes prefer text and likes.
- Messenger only is also a success, see Whatsapp/FB messenger, but some people have the need to expose themselves to people outside their groups.
- Pinterest, Instagram and Google+ have their own public which mostly likely are also in FB. They use it for difference purposes.
- Twitter, well this one it's difficult. First of all most of the communication is public and some users are not interested in that. Also there's a lot of self promotion messages which does not mean it will engage users to communicate. Finally Twitter tries to reinvent itself and the features are not consistent. i.e. For several weeks they enabled translations and after it was disabled. Twitter might have a chance to engage more people with Tvshows, movies, music and personalities.
Facebook after all is the social network which is easier to get started, makes a balance between public and private/groups, lot's of features available (games, messenger, groups etc...) and families and friends in the same feed. I guess it's pretty hard to beat that currently for other social networks.