I hear it isn’t what it used to be as well. They used to do in-person interviews, then they moved to un-proctored quizzes to prove skill, which I find to be a unique and mostly-accurate gauge of skill in a particular area. That said, I don’t know how common cheating would be. If it’s high, that certainly explains why companies don’t seem to put much merit on them.
Also, there’s the irony that TripleByte went from a language-agnostic in-person (virtual) interview to very specific quizzes. So instead of saying “this dev knows how to dev”, they now say “this dev knows C#, Python, SQL, and JavaScript”