[na85]

>Isn't that a very solved problem?

Not in my experience. Most solutions I've found tended to be more work/brittle than just emailing the file to myself, which is a sad statement about ad hoc file sharing.

Other solutions like $ python -m SimpleHTTPServer or spinning up an ftp server work okay too but sometimes you run into NAT problems if you're traversing e.g. residential home networks.

Magic wormhole is simply the best way to get files between arbitrary points A and B, irrespective of operating systems or NATs and firewalls in between. I've never had it not work.