And of course you would have a newsfeed filled with posts from the future telling you about your friends and family.
Because social networks have this chicken-egg problem in which you need to bring a given critical mass of users, and you can't predict their number, but it must have enough gravity to attract more users and keep growth.
I failed my own business-focused SN for that reason, even after attracting companies such as Sherwin-Williams and some taxi cab companies. That was a few years before The Social Network movie, before people started caring about privacy and ads. It was easy back then.