Marianne Stecher just wants to shift some media from one Apple device she owns to another:
I’m trying to send a video from my Mac to my iPhone. I don’t have cell service so I can’t send through a text, only over Wi-Fi. I shared it through iCloud sharing so that I could save it to my phone and upload it on my account, but it won’t allow me to save the video to the phone. Emailing doesn’t work either. A 19-second video is apparently too large to send through email.
There are clearly a bunch of constraints affecting Marianne, as some of what she suggests should work and isn’t.
Use AirDrop. With a recent enough vintage Mac and iPhone, AirDrop is the easiest way to transfer images and videos, pass URLs, and hand off other kinds of files and tasks. It requires both Bluetooth and Wi-Fi.