It's meaningfully different because once the access is confirmed, it respects you. You can easily save a copy forever. You could even copy/paste from it. DRM specifically makes it impossible for you to do that. It just doesn't just verify that you paid, it blocks and interferes what you can do with the content.

It doesn't become DRM just because some people choose not to make a backup copy. That would be like saying everything I can see with my eyes but choose not to photograph has DRM on it (or effectively is DRM). That's clearly not true, as I could at any time decide to photograph my surroundings and the objects I'm photographing aren't going to restrict my camera.