Why? Because dwelling on revenge keeps the original wound open. After the act, the avenger is left with an echo: Now what?
This is often why the "Living Well" adage is cited as the best revenge. It is the ultimate form of The Dulce Venganza because it creates a scenario where the avenger gains happiness while the antagonist is left only with the bitter knowledge that they have been surpassed. The Dulce venganza
In real life, Dulce Venganza often takes non-violent forms: Dulce Venganza often takes non-violent forms: