Why aren’t we using SSH for everything?

For one thing, SSH performance for large transfers is abysmal over high-latency links. SSH uses a small TCP window size because it was optimized for quick response, not bulk transfers. (After all, it was designed to be a remote shell protocol, not a generic file transfer protocol; scp and sftp were added after the fact.) And unfortunately you can't currently specify a different buffer size even if you wanted to. More information can be found here: http://www.psc.edu/index.php/hpn-ssh

Because it's not a very good protocol. Adopting it, instead of HTTP/2 and TLS 1.3, basically gets you everything that is bad about TLS (most notably, a legacy of 1990s cryptography) and everything that is bad about SSH (poor performance, extreme complexity), and leave you with no upsides. For instance: the HTTPS stack will, with effort, allow you to opt in to protocol forwarding, via mechanisms that were designed to prevent accidental forwarding. The SSH stack, on the other hand…

Amazingly, the chat example still works: $ ssh chat.shazow.net * prepperdev joined. (Connected: 35) [prepperdev] anyone here? :)