Happiness is a meme to get people obsessed with hedonism. Nobody is actually "happy" for longer than passing moments, much like lust, and acting like it is the be all of existence is one of the foundational stones of the entire Leftist movement and its promotion of degeneracy. Heck the notion of it didn't even exist in its current form until the late 18th century.

People associate happiness with a separate feeling removed from virtue, success, or the numerous other principles that make a person a "good person." But by it being so they can still convince themselves they are "good" while committing acts of degeneracy.

For example, women most often initiate divorces because they aren't happy. This allows them to justify it was a necessary thing, and to hell with the massive damage it causes to everyone else around them. But, the goal of happiness demands they do so, even when it is impossible to ever truly reach.