Adding gamification adds a short-lived hedonic happiness hit that doesn't last very long. Sometimes we'll see articles about "making apps delightful" by adding a shiny button to an app that looks great when you hit "task complete". By the 100th time you click that button, that hit will have worn off.

Gamification works as a crutch at best. Instead, designers should really aim for the "eudaimonic" side of the task. E.g. your room is now clean. Or a workout app could help users better keep track of their strength / ability to lift heavier / better form over time, and reflect on their improvements. These will make users feel a lot more gratification.