File transfer sure is hard. Why is it so hard?

• My favorite for 1-1 file transfer is magic wormhole protocol via rymdport, although it has significant bugs
• There is also croc although it needs a comprehensive security review (along with magic wormhole)
• For 1-to-many transfer, I usually prefer Bittorrent
• For many-to-many, I like SFTP. Yep, good old SFTP. My preferred server is SFTPGo. It supports S3-compatible cloud storage as a storage backend and allows you to mount as many of those as you want in a virtual filesystem scoped to specific users. Very good. I host it at https://files.qlyoung.net.

If it's iOS to iOS and just 1-to-1 or 1-to-many, Airdrop works well. Many-to-many quickly becomes unmanageable.

For cross-platform iOS ↔ Android transfers, I usually reach for snapdrop. However, for transfers of more than 1gb or so, it starts to get sketchy with phone lock timeouts and background task kills frequently resulting in failed transfers.

I'm not aware of any reliable and broadly available tool that exists in this space. A magic wormhole client for mobile would be amazing. Do you know of one?

I made this page with its name before seeing this appropriate XKCD: https://xkcd.com/949/

At least I'm not alone.