But if you already have ssh set up for the target machine, is there any advantage such as speed or recoverability vs scp?
But wormhole has turned out to be more usable in some cases. I've had days where I'm sshed into a bastion host, then sshed from there into a server, then cd'd into a deep directory with lots of spaces and quotes and shell metacharacters in the path, and then found a file that I wanted to copy out. To do that with ssh, I have to first configure ProxyJump to let me reach the internal machine with a single ssh command, and then figure out how to escape the pathname correctly (which somehow never works for me). With `wormhole send` I get to skip all of that, at the cost of having to do it once per file.