Kids don't really use email these days, or usb sticks. They share more than we ever did, but directly via apps or mobile which doesn't work with "files". It seems reasonable in this case the thing missing is the abstraction of a "file". Think of how your phone works, you share pictures, video, text, posts, etc. but never files. Sharing to email is my phone's 5th or 6th priority option. It comes after a boatload of social media options, messaging, online storage, even some sort of AWS application I've never even launched.