The ATProto (the federation protocol on which Bluesky is built) may inadvertently worsen online discourse through bad commercial incentives.
In a federated system where users can easily switch platforms with their social graphs intact, platforms will compete for users/eyeballs by optimising for engagement rather than quality content. The outcome may be that "responsible" platforms that moderate well become small, irrelevant echo chambers, while platforms that embrace sensational, low-quality content grow rapidly and dominate public discourse.
