Bluesky Challenges ActivityPub Fragmentation

The key issue is that ActivityPub governance lives at the server level, so one big product launch can fragment the network instead of unifying it. When large Mastodon admins choose to block Threads, a user on one server may be able to follow a Threads account while a user on another cannot. That makes the fediverse feel less like one social graph and more like a patchwork of local policy decisions, which favors products with one default rulebook and one consistent user experience.

• The anti Meta push was not just theory. In June 2023, instance admins created the FediPact to pre commit to blocking Meta run servers, showing that federation decisions in ActivityPub can be made by hundreds of independent moderators before a product even launches.
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• Threads kept expanding federation anyway. Meta enabled fediverse sharing in March 2024, added broader sharing in June 2024, and by June 2025 said Threads had interacted with more than 75% of fediverse servers. That means defederation is meaningful, but not strong enough to stop a large network from entering the ecosystem.
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• Bluesky solves this differently. AT Protocol lets people move identities and data between Personal Data Servers, but the network still routes through a smaller set of shared services like relays and app views. In practice that gives users more portability than a closed app, while avoiding the server by server policy sprawl that defines Mastodon.
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The next phase is a contest between local autonomy and network coherence. ActivityPub will keep attracting communities that want each server to set its own rules, while Bluesky can win mainstream users if it keeps open portability in the plumbing but delivers one predictable experience at the app layer.