> You always had to keep whatever youtube video downloader you were using updated at a minimum.

Of course. I always try with the latest versions of yt-dlp.

> For a good while login cookies were only required for downloading restricted videos (whatever youtube considered 18+). Now you need half a web browser to do anything and the update cadence is even crazier.

Yeah at some point in the past I had it mostly working. But basically now, what should I do? Maybe host a VM with an actual browser (not headless: just the real thing) and log into a Google account and then what, use yt-dlp from the same IP?

Basically I don't get it: no clue what needs to be done for YouTube downloads to work reliably (and I'm not talking 18+ stuff: actually I had zero idea there were even vids considered 18+ on YouTube).