Lots of people are not tech savvy. It’s entirely believable that someone who doesn’t understand why their stuff is in OneDrive in the first place also wouldn’t understand that they could move data somewhere else to fix the issue.

Most people I know who don’t work in tech have 90% of their stuff sitting in their Desktop and the other 10% in Documents. These people don’t know how to create a folder named “c:\stuffidontwantinonedrive”.