Putting social media on blockchain increases the control of network particiants like creators, users, advertisers, developers and moderators. That's why we put social media on blockchain.
While blockchains have been long touted as the solution to decentralize the internet, they have struggled beyond financial applications because of heavy data storage needs of the internet
The original internet protocols just transmitted data but did not store or index it. This lack of storage allowed big tech companies to fill that void.