20 years of saved videos vanished

I've been saving videos I like, music and various other topics, probably over 100 clips, for the past 20 years. Even when watching YouTube on TV, if I see something I like, I simply Save. The other option is Watch Later. I noticed last week I only had the Watch later option. Today, tried it again, Watch Later option only. So I fired up the laptop and was shocked to see zero content on my playlist. All gone, erased, deleted. They were there a few weeks ago when I last accessed them. No was 100 creators all decided to delete their content on the same day. What happened?