If Google really wants to, they can crack down on yt-dlp, and I assume that if enough people are using it, they're likely to do such a crackdown. Like, this works for the moment, but...
My ip was blocked a LONG time ago by google for using yt-dlp. Works with VPN but nothing else. Fun times. I think I only pulled a couple of videos off for archival services. On my own channel non-the-less.
You might try again. I was blocked for a couple weeks after I pulled a bunch of videos from a channel using yt-dlp, and for a while YouTube required an account (which I will not get) from that IP. But a couple weeks later, things were working again.
It will happen eventually. All they need to do is start new/rotating keys on wildvine and put the ads at random times right in the stream, then disable fast forward if you use it to skip ads. It'll be a UX hit, so it'll need to be worth it to them.
In the end, they can't stop us from HDMI capturing and using comskip to detect / remove but there are a million ways to play tag between where we are now and that which don't require people posting videos to pirate bay :)
Interesting, I had figured that was possible in principle but hadn't kept up with what was actually around.
But still, the HDCP stream is decompressed video, so if you want to save it, you'll have to either put it through yet another layer or lossy compression, or burn a ridiculous amount of disk space compared to the compressed stream that Youtube sent to your computer.
We'll see how things go. Google in the past has made occasional modest gestures to get in the way of downloading, but they haven't made serious effort to prevent it. Who knows whether that will last.
I've been doing this with band love videos and storing them on a hard drive. One I love got taken down and almost lost a while back and it's made me paranoid ha