I can answer for my kids. Everything they do is in the cloud and accessible on any device. I'm not sure they'd understand why anyone would want a thumb drive.

As for attachments on emails, they don't (even for a 100% online highschool). To turn in a paper they can just hit "share" and select their teacher.

Files and filesystems are almost dead to them. There is a little hope... My son googled to learn why a game was going slow and answers indicated he should delete the temp files. That was his first experience needing the file explorer.

As someone who grew up with DOS and turned in CS homework on a floppy disk, it is almost hard to watch.