I think my main criticism of this article is that Signal today isn't proving that this is true.

Yes, federation makes all of this stuff harder. Of course it does. There are problems you have to solve in federated systems that you don't have to solve in centralized systems. And it used to be easy to point at platforms like Matrix/Element and say that they were still struggling to get encrypted chat turned on by default, and that was proof that federation didn't work.

But in the years since this article was written things have started to change. And now the interesting stuff going on with Matrix isn't E2EE chat, it's P2P encrypted chat, it's using Matrix as a drop-in securely encrypted data-transfer for web apps. It's all of the innovation on how metadata gets encrypted that Moxie claimed was going to come out of centralized platforms, and never did. Meanwhile, Signal is still trying really hard to decide whether or not usernames should exist.

It seems clear to me that federation isn't the entire picture, because the federated apps I'm paying attention to are seeing more active development and iteration on user-facing privacy features than Signal is.

Separately, I think Moxie's argument that switching costs between networks aren't an issue has not aged well. And I also think Signal itself demonstrates this point; there's a reason why Signal falls back to relying on one of the most insecure messaging protocols in existence, and there's a reason why Signal makes privacy concessions like tying itself to phone numbers and announcing to you when other contacts join Signal. It does that because actually switching costs are very high, and even Signal can't get people off of SMS unless it maintains compatibility with that network. Even Signal as a centralized platform hasn't been able to get people to switch off of literally the worst messaging service we have today on almost every technical level.

So my main criticism of Moxie's take is that I see federated systems that are overcoming some of the problems he talks about, and I don't see Signal innovating in that space to the same degree (not that they're doing nothing, just that they're not doing nearly as much). And my secondary criticism is that I think he's dismissive of some of the downsides that come from centralization, including downsides that have hurt Signal's adoption rate among ordinary users.

The main reason I like Signal so much is that it is highly audited by security professionals that I trust, that it's been around for a while and proven that it is secure, because it is a small app with less attack surface, because it's seamless on top of SMS, and because I think Moxie is a good, trustworthy coder with solid moral principles about privacy (part of why I'm disappointed to see him leave the company).

And all of that is still true today, but since this article was written I haven't seen the level of supposed innovation that I was told was going to happen. It's the federated platforms doing the exciting stuff, and meanwhile Signal is good because it doesn't change much and it still just kind of reliably works the same way it always used to. It's ironically almost the opposite of the situation Moxie claimed was going to exist.