Started downloading my Youtube liked videos back in 2009 (and keeping it updated ever since). +10k videos ~1.5 TB. It's pretty much nothing and a huge chunk of them gone forever from the site, especially pre-2010 ones.
Automatically you can only download the most recent 100 liked videos. So if you have a huge library first download the list (even Google Takeout supports that), you just need the video IDs then feed it to yt-dlp.
The rest, like quality, are personal preference. Like I usually max at 1080p and never download DASH videos.
When you are up to date you can still automate it. For example download once a week but I pretty much download everything asap even manually because I know Google can remove it quick or even sometimes the uploader.
Yeah, that happened to a channel I loved several years ago [0]. I've been scouring the internet ever since then, looking for mirrors of the channel, and one video in particular [1]. It's a long shot, but maybe you or someone else reading this could help, so I'll leave the links here:
