A place for those who would be marginalised by their own community, gay, religious apostates etc etc.

Communicating with relatives on the other side of the world.

Maintaining old friendships that would have died due to distance.

Somewhere to find like minded people.

Somewhere like hacker news (I count it as social media top) where I discovered great books, expanded my horizons and learnt that there were other ways at looking at the world.

Anyway, it's not all bad :)