Happiness consistently eludes us as long as our understanding of happiness is limited, by and to, a common level of consciousness ("ignorance").
The Shorter Discourse on the Mass of Suffering indicates that repeated bouts of greed, hatred & delusion cause anguish, and that at the very root of this spiritual anguish is sensual desire (kama).
Sadly, most of us already “understand that sensual desire provides little gratification and often leads to much suffering” but because we’ve never experienced anything better, we "remain in thrall to the joys of sensual desire.”
And how can we experience the transcendent bliss we're really after? Deep states of meditation.
Stephen Batchelor. “After Buddhism. Rethinking the Dharma for a Secular Age.” Yale University Press, New Haven, 2015.