The author examined the distribution of instances in the fediverse. Given that many instances are hidden behind CDNs like Cloudflare or Fastly, the author employed ActivityPub’s functionality to discover the actual hosting locations of servers. More than half (51%) of the fediverse is hosted within a single hosting company. The author suggests that the fediverse hosted mostly with a few major providers, deviates from its initial objectives.
I always see ActivityPub as a simple glue to existing model of social media networks.
If we want to decentralize further and further the end goal would be a serverless message format with public/private key cryptography build on something like Yggdrasil or GnuNET network.