without opening it up physically there is no way to make it stop or get the raw stream before it's displayed
Naturally that got broken too, and even worse, broken when it's only supported by a minority of devices and content, because the more devices and content it's used for the easier it is to break and the larger the incentive to do it.
If you tried to require that for all content then it would have to be supported by all devices, including the bargain bin e-waste with derelict security, and what do you expect to happen then?
That’s why a lot of low end Android devices often have problems playing DRMed content on the Web: their keyboxes got cracked open and leaked wide enough for piracy that they got revoked and downgraded down to L3.
the real pain in the butt in my present is Patreon because I can't be arsed to write something separate for it. as-is, I subscribe to people on Patreon and then never bother watching any of the exclusive content because it's too much work. some solutions like Ghost (providing an API for donor content access) get part of the way to a solution, but they are not themselves a video host, and I've never seen anyone use it.
That's not real DRM then. The real DRM is sending the content such that it flows down the protected media path (https://en.wikipedia.org/wiki/Protected_Media_Path) or equivalent. Userspace never sees decrypted plaintext content. The programmable part of the GPU never seen plaintext decrypted content. Applying some no-op blur filter would be pointless since anything doing the blur couldn't see the pixels. It's not something you can work around with clever CSS. To compromise it, you need to do an EoP into ordinarily non-programmable scanout of the GPU or find bad cryptography or a side channel that lets you get the private key that can decode the frames. Very hard.
Is this how YT works today? Not on every platform. Could it work this way? Definitely. The only thing stopping them is fear of breaking compatibility with a long tail of legacy devices.
