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.
Not to give any judgement on whether usage of a CDN is good or bad. But I think it is a bad idea to talk about decentralized hosting and decentralized ownership like they are identical. The problem with social media the fediverse is solving isn’t that all social media goes down when CloudFlare/Facebook CDN goes down. It’s to be independent of one organisation or even person that can ruin the fun for everyone. If CloudFlare bans every instance, the owners are still in control of their DNS names and can just move to another CDN or their own reverse proxy/cache
Please see my statement on this matter under @themurphy@lemmy.world’s comment.