I mostly gave up on this. But I would say, a link isn’t enough if you want to keep them. Make your own archival copy. I can’t tell you how many articles I saved to read later were gone by the time I actually got around to wanting to read them. The same goes for YouTube videos. Some things I was able to track down on archive.org, but not everything.
Is there something like archive.is but for YouTube Videos?
Using the wayback machine can work if you have the exact video link, but it's not guaranteed that they'll have it
You can occasionally find a torrent out there of some channels entire video log
Other than that, no
If you come across a video that you really want to save, just use ytdlp to download it