Yt-dlp: External JavaScript runtime now required for full YouTube support

Perhaps a stupid question, but is there some reason I can't potentially fall back to recording my screen / audio in realtime and saving videos that way? yt-dlp is obviously far superior to this, but just thinking about what my fallback points are.

You definitely can, it's just 1) vastly slower, and 2) you have to recompress the decompressed video, which loses quality. It's therefore an option of last resort.

Most people want to be able to download 5 hours of video in the background in 5 minutes. Not wait 5 hours while their computer is unusable.

I wonder if it has to be a real computer, display, and camera, or if doing it with a "headless display" that is nonetheless being fed to a "video recorder" would work...

Funny how it'd be like The Matrix...

It depends on a lot of factors. But even if it works in a virtual machine, your CPU is going to be pegged at 100% the whole time to handle the re-encoding. Unless you use a hardware h.264 encoder, but then the quality is pretty terrible since it's explicitly optimized for speed over quality and isn't tunable the way software encoders are.

It's always doable, it's just an option of last resort. You always just want to access the original compressed bitstream if possible.