I realize this is a dumb question, but what's a good way to do this between an iPhone and a MacBook? Airdrop is disabled (by policy), iCloud storage is full (because I'm lazy), and I use syncthing on every other device, but I haven't found a client I can use on my work iPhone.
If they're on the same network, cross platform, open source airdrop alternative
https://github.com/localsend/localsendI like LocalSend and Landrop. The latter performed better when I sent large files. However, neither of them does it automatically; you have to manually do it every time, which is okay since they don’t claim to be sync software.
Maybe syncthing fits your use case better?
https://syncthing.net/