People used FTP for decades, too.

And they still do. I worked at a market maker that used ftp over ssh to move over 10b a year in trades between its various offices.

I hope there is no such thing because that would be insane. If you mean SFTP, that's actually a completely different protocol and is part of SSH.

If you mean FTPS (which I suspect you do as I actually had to set up something similar at one time), that's FTP over SSL and has nothing to do with SSH.

Your point still stands though: some of the background "FTP a CSV file with a cronjob" crap that goes on in the background would horrify anyone.

You forgot that SSH can be used to tunnel arbitrary TCP streams. FTP over ssh, http over ssh, etc.

Sadly, all three are used and none of them should be.

Nope, ssh tunnel.

Has anyone told them there might be a better way?

What is better than (S)FTP? Or do you mean MFT, AS2?

SFTP shares only those three letters with FTP but is otherwise a completely different protocol.

It's also a counterpoint to one of the OP's points which is that trying to secure email is a dead-end that we should give up on. It may be possible, though very difficult, to transition to secure email. But it would have to be a brand new protocol not tacked-on to the current system. The way that SFTP is the appropriate upgrade path for FTP and not FTPS.

The interface of sftp is largely the same as ftp. You can give someone an sftp client, username, and password and they wouldn't be able to tell the difference.

A new e2e protocol that works just like email does would be excellent, but we don't yet have that. Signal &co are chat apps with a different feel and purpose and other than matrix and xmpp not federated, which is a non starter for many entities.

Yes I hope it is SFTP and not FTPS.

There are some things we could easily give up to get encrypted mail. For example, setting a max delivery time to allow ephemeral keys.

But there are other problems with encrypted messaging, and I'm particularly thinking of spam. How does Signal/WhatsApp manage to keep a lid on it? Would that be possible in a federated system?