This Invidious instance still works. Don't push it too hard, though: it's all we've got.

Also, if you log in to YouTube in Chromium or something (assuming you're on desktop) and then use yt-dlp with the --cookies-from-browser chromium argument, it should work. This is also possible on Android via Termux and iOS via iSH if you copy ~/.config/chromium to the app.