This is network-specific. It's been going on for a few months at least. yt-dlp itself still works without sign-in, if your network is not "suspicious".
Always worth making sure you're updated to the latest version of yt-dlp, but this is probably a network thing.
Almost has to be. 2400W would put it completely outside the consumer market. Consumer PSUs don't go that high. Home power outlets don't go that high unless you have special electrical work done. I can hardly imagine what a cooling system for a nearly 3KW system would look like.