Linux

I think a decent alternative would be to use yt-dlp to download the songs you listen/watch on loop most often, then use a basic video editor to cut out the start and end bits you don't want. Plus, that means you can listen/watch to them offline using your preferred video player of choice! This, however, isn't as good if you're the kind of person who likes listening to new songs, and it won't count how many times you've played each song.

I don't know whether it has all the features you mentioned, but https://www.youtuberepeater.com/ is still up

Infinite jukebox has more complex looping and I think is just a website, but its super cool. I haven't used it for ages, but it may be worth checking out