In ten years time YouTube will be entirely inaccessible from the browser as the iPad kids generation are used to doomscrolling the tablet app and Google feels confident enough to cut off the aging demographic.
They’d need dedicated hardware to enforce any kind of effective DRM. Encrypted bitstream generated on the fly watchable only on L2 attested device.
Netflix is already there for 4k streams
And it's an entirely useless effort. No idea how it is done but the internet is full 4k rips.
They find devices that are easy to hack (and I mean rip and tear) and extract the decryption keys from each of them, from what I have heard cheap chinese tvs and set top boxes, they extract the keys from the chips (hardware hacking, heard some even use microscopes to read the keys by hand), and then use them to decrypt streams, I heard that they catch them pretty fast to they use like 1 device per season. This is why they use mostly stollen devices.