In everyday life, the boomerang effect is associated with the idea that all the evil done by a person will come back to him. This is part of the concept of a just world, where bad things happen only to bad people, and all the villains get what they deserve.
The confidence that the offender will definitely be punished by fate is a psychological defense mechanism. It helps to survive the feeling of helplessness, injustice, anxiety. In a sense, it is a way not to get hung up and move on.
If such an approach works and really helps to step over the problem, then everything is fine: protection, as it should, protects us and our psyche. As long as it does not turn life into waiting for the boomerang to finally fly to the offender. Because the world is unfair, not everyone gets what they deserve, and bad things happen to good people too. Life is a big randomizer.
However, there are cases when the boomerang effect definitely works well: if a person believes in “response” and tries not to do anything particularly evil, so as not to get it back. On the other hand, you can do nothing bad just like that, and not because of fear of punishment.