This doesn't change the fact that 99% of things people give credit for to social media can be easily done without mediation through a multi-billion dollar corporation.
Neither does it change the fact that Twitter and Facebook have a whole slew of horrible social effects. Centralization of the web, political polarization, emergent mobs trying to ruin people's lives, rise in depression and suicide rates, normalization of global surveillance, normalization of censorship, etc, etc.
Jaron Lanier has some interesting thoughts on the economy behind some of this: