[belorn]

DRM is not about protecting content, its about lock-in and keeping users on a single platform. Security researchers (schneier) has written about it. Content creators has written about it (Doctorow's Law), advocates has written about it (EFF), and of course users has written about it endlessly. The only people who argue that DRM is about protection is the publishers.

There are a few schemes, which normally do not even count as DRM, that is intended to protect copyrighted material. Encrypted TV channels is a primarily example. A streaming service could copy that scheme, but delivery physical tamper-proof boxes that do key-exchange every few minutes is quite expensive. Alternative they could what YouTube/Twitch do, which makes copying a stream about as difficult as downloading a pirated version from a torrent site (ie, you need to use a third-party software). For movies, it is the best protection as you can get without having to distribute physical boxes.