I felt like Hell Girl did a good job of showing why it’s a good thing curses don’t exist. People would be willing to curse each other for minor things out of anger, and our society would not be able to advance. I doubt many people would escape being damned to hell by vengeful peers at primary school.
The premise is any person can send anyone to hell, but in return they will be sent to hell. Many people are so blinded by revenge they still do it, only to realize afterward it wasn’t worth it. Often, it turns out their enemy wasn’t their enemy, didn’t deserve it, or was mostly innocent.
The story also attacks hitobashira / human sacrifice in old Japan. The main character was buried alive 400 years ago to appease an angry God, and awoke as an angry spirit. Once again, we’ll be better off when we remove all traces of that horrible past. You never know when embracing a lie will lead to reprehensible thinking by the better standards of the future.
Here’s the OP, which I love.
Another manga that takes a look at torture in hell is Jigokuren. It’s a romantic comedy where the main character is tortured repeatedly in hell.