Capturing the digital video output is supposed to be prevented by HDCP encrypting the signal, but in practice that's pretty well broken. That is a (slowly) moving target though, each time they roll out a new HDMI version (e.g. for 4K) they get to enforce a new version of HDCP which needs to be broken all over again.
I don't think the version of HDCP attached to HDMI 2.1 has been broken yet but that's kind of a moot point because no current video formats require more than HDMI 2.0.
It's hilarious to imagine the meeting where they finally convinced themselves they could put worthwhile lasting encryption in consumer devices with a 10 year+ installation lifetime.
I suspect bad encryption still does exactly what they intend, because it means there is no simple one click solution built into an OS or browser to download streaming media for later watching or sharing with friends. For example, a lot of regular modern OSs have the ability to rip and share an unencrypted audio CD in a simple intuitive way with no shady pirate software to install.
It's a legal hurdle, not a technical one that prevents the 'above the board' software suppliers from adding this feature.
Pirates clearly are able to extract the 4K video and upload them to torrent sites, but the average media consumer would rather pay a netflix subscription fee that deal with the shady underworld of those sites with the virus installing and crypto mining popups, warning letters from your ISP, etc.
They've managed to make it hard enough that the number of people that do it is insignificant to their bottom line.
Torrenting hasn't been the most popular form of piracy for a while: many subscribe to a couple streaming services and use pirate streaming sites to fill in the gaps [1]. This is so prevalent that even entertainment industry talent use pirate sites for both series [2] and sports [3]. Takedowns mean that sites change from year to year but FMHY-style curation makes casual piracy easy: one can always find a site with 1080p content (unsure about the bitrate though) and great UX.
Hilarious ... if you don't understand modern DRM, yes.
Modern games console security shows you can easily build DRM that lasts 10+ years. Xbox One came out in 2013 and was never properly breached during its entire lifecycle, Xbox X/S replaced it and have also not been breached. Microsoft figured out how to make strong DRM ~15 years ago on devices they design and manufacture. There's nothing wasted about that effort given that it lets them subsidize the console costs and block cheating.
All the HDCPs are broken by those cheap Chinese splitters which downgrade it to 1.4 (allowed by the specs for some reason) and 1.4 is thoroughly broken. At least that was the case last I checked.
I don't think the version of HDCP attached to HDMI 2.1 has been broken yet but that's kind of a moot point because no current video formats require more than HDMI 2.0.