Examples:
https://azchart.info/
https://trshow.info/
I don't speak the language there, but it is quite obvious the site, or a user on it, is copying YouTube videos, and somehow even the comments are present in the comment section? It doesn't seem to be some kind of embedded YouTube site - I can't think of how they copy all the comments with names and avatars.
The reason I am asking this is because they copied a video where I was commenting years ago, and back then I used another nickname. I am trying to void this nickname from the internet, and these obscure sites are the only ones still popping up.
I am trying to contact the sites (I have my doubts about their GDPR compliance), but I want to know what their background is in general. Only reason I can think of is some kind of mirror for countries where YouTube is blocked? But it sounds like a lot of work to embed every single YouTube video with comments.