Ask an email administrator how well decentralization works at scale.
It should be concerning that email has re-centralized to deal with all the problems that come from federation and decentralization.
It should be concerning that email has re-centralized to deal with all the problems that come from federation and decentralization.
As someone who administrates their own email server and works at an SMB who administrates their own email servers, it works quite well and doesn’t require centralization.
I've done a lot of a lot of email administration over the years, servers with 100,000s of accounts, and you walk a very fine line in being able to communicate with the rest of the world. Your IPs must exist in certain blocks (or at least not be in banned blocks). You must block outgoing spam messages at a much higher rate and quality than google/hotmail do. Get yourself blacklisted for any reason and expect to disappear from the internet, meanwhile no one is going to block the largest services.
50 year old decentralized protocol has problems, so decentralized protocols can't possible work. Just like 50 year old computer can't play doom, so doom doesn't exist.
The basic problem with email is that it assumed good-faith participation from the parties involved. It was assumed that only legitimate actors would have the resources to participate and they would always be well-behaved. This, it turns out, was flawed on several counts. For one, it assumed legitimacy could be assured. For another, it assumed legitimate users would be well-behaved and would never abuse services for gain. For a third, it assumed account takeovers or other impersonation attacks wouldn't happen.
Every de-centralized system that aspires to not have email's problems needs to take them seriously.