Companies have an {obligation, fiduciary duty} to maximize value for shareholders, therefore they have no choice but to do horrible things to {users, customers, the environment, civic institutions}
Presumably, decentralization, federation and open source will eliminate the profit-maximizing corporation, thereby stopping all the horrible things.
The problem with this reasoning is that it only addresses one side of a two-sided transaction. The corporation doesn't transact with itself. The other side of the transaction is the user.
What if every user was willing to pay $5 per month for a "clean Facebook" without ads, without surveillance, without psychological profiling, without selling private data to malevolent third parties?
If every user paid $5 a month, Facebook could continue their current business with the best computer science talent and a global network of data centers.
If every user paid $5 a month, Facebook's shareholders would do fabulously well.
But of course, that's a ridiculous proposition. Only an infinitesimal number of Facebook's 2.2 billion users are willing to pay for the service.
Since a social network only has value to a user when all the user's friends and family are also on the network, a Facebook that only has a few people willing to pay won't be very useful.
Advocates of decentralized social networks need to explain (1) who will pay, and (2) how to get enough users to make the network valuable to a typical user.
Until we figure that out, we're stuck with social networks that are free for users, monetized with advertising, and regulated by the state.