You don’t own an ebook or an MP3 either. You have a license. You still legally aren’t permitted to do whatever you want with it. (And because virtually anything you do on a computer requires copying, there is no discrete “file” for you to own like you do physical media.)
DRM is a tool that companies use to screw customers out of controlling their own libraries, but content being DRM-free doesn’t change anything about what you legally can or can’t do with it, and doesn’t turn your license into any kind of legal ownership.