Yes social network use a lot the datas of users, and some users dont want to share their datas with big compagnies most of time. Thats why I think decentralization is very important for the future of social network.
That 's why with decentralizing, Sphere can compete with Facebook for sure. We have seen Blockchain technology fight against traditional ones in many aspect, finance, data storage, science research, etc. Now it's time for social network.