The quality of the original comes from the dynamic of the main cast. They're each awful people in their own distinct way, and they each basically incentivize each other to be even worse than if they were surrounded by purely normal or decent human beings. That's entertaining. It's basically the anime equivalent of It's Always Sunny in Philadelphia. Imagine if you had a show that was just about Charlie or Mac when they were in high school? That might be kinda entertaining, but the premise artificially confines the character and what they can do.