> You could solve that by Federating, except... Federation would be lovely if you could actually deliver Signal's goals and do federation for free, but what we always see from proponents of Federation is that was their goal and so they're done. Oh you wanted security? Sorry, we federated everything, so you'll need to get every single member of the federation on board with every single change you need, we know you can't get that done but that's fine because our priority was federating stuff, so we are successful, shame about your goals.

I have a lot of serious criticisms of Matrix, to the point where I don't recommend it to friends (yet?), but this feels like an unfair and unserious criticism. I don't think you can fault their motives.

And as another user points out, if Signal goes down in the United States because of legislation, so much for the supposed convenience of your non-federated central server approach! If that happens I'll take Matrix over nothing, thanks.