Very true, but have you tried just reaching out to someone via email on Matrix in practice? I tried with Riot and am not able to do that. Maybe just a bug, but if you want the real Matrix experience, you need a Matrix account. Don't get me wrong, I do love Matrix, but I also love XMPP - both not spectacular successes so far. AFAIK, the French Matrix version is even locked down and does not federate across the network.
You can reach out to folks by email in Riot by hitting "start chat" and entering an email address. I'm not sure how much easier we can make that ;)
We should run a general purpose email bridge though, and in fact there's a massive public sector outfit asking for such a thing currently so it'll probably happen sooner than later.
In terms of Matrix not being a spectacular success - well, that's a matter of perspective. The intention for France is absolutely for it to federate with the public network (once there's are sufficient border gateways in place). And France is far from the only high profile Matrix deployment out there, it's just one that we can speak about. But eitherway, COI looks cool, and I hope it helps OX sell more mail servers :)
