Well, or a group of users can come together and attach their identity to a DNS server run by an admin they trust. If I register pinksky.com, it is fairly cheap

Well, or a group of users can come together and attach their identity to a DNS server run by an admin they trust. If I register pinksky.com, it is fairly cheap for me to hand out subdomains to Bluesky users -- certainly easier than running a Mastodon instance. I think the questions about indexers and firehose servers are more relevant to the question of centralizations. Identity is much easier to solve.