Many of the debates in bioethics are really about competing visions of happiness. For example, if happiness is a mental-emotional state of good-feeling, then negative or bad feelings are tantamount to unhappiness, and an ethical system which forbids actions which might relieve bad feelings could be viewed as cruel or inhumane. Or, if happiness is viewed as having positive self-regard—being pleased with oneself—then an ethical system which caused guilt or shame for one’s actions would be a cause of distress. Conversely, if happiness is attained in virtue, then, somewhat paradoxically, one could be happy even when feeling distressed or dissatisfied, for happiness would not be understood to be “feeling good” so much as “being good.”
A recent essay in The Guardian  on anti-natalism, the position that “life, even under the best of circumstances, is not a gift or a miracle, but rather a harm and an imposition,” and thus that it is morally wrong to have children and impose harm, depends on a vision of happiness. For anti-natalists, the goal “is to reduce human suffering,” and since life “introduces the guarantee of some harm,” it is better to not exist. “Living things can be harmed. Non-living things cannot be harmed,” as one anti-natalist puts it.
Of course, from those premises, it’s quite obvious why euthanasia would be judged permissible, for if life is deemed  “unbearable,” and non-living beings cannot be harmed, no-longer living would end unhappiness. Abortion, likewise, appears quite sensible, either to render impossible the unhappiness of the unborn child, to end the unhappiness of the mother, or to further the possibilities of happiness for the mother (or father, or siblings, and so on).
The very existence of moral systems might be seen as wrong-headed, for if a moral system results in guilt-feelings , and happiness depends on my positive self-regard, then morality itself is a source of harm. Just as many judge that we are better off—that is, happy—if we do not believe in an all-watching God, so too we might judge ourselves well-rid of moral judgment itself.
Our society is obsessed with happiness, especially, as a recent Aeon  essay by Cody Delistraty terms it, “performative happiness,” which “holds that bad feelings must be avoided at all costs,” and that even “neutral or mundane life experiences” are to be avoided. I might call this “Instagram Happiness,” a vision of life “composed of a string of ‘peak experiences,’” where all non-peak experiences, let alone negative experiences, are viewed as intolerable. The point of life, in this vision, is “having and seeking” positive emotions while actively pushing away any experience of unhappiness, understood as a negative feeling.
Such a vision would not comprehend, indeed would have a horror of traditional moral systems which either downgraded the importance of subjective states of well-being or viewed happiness as conterminous with being virtuous, however one felt about it at a given moment. If there was a duty to protect the life of the unborn, say, or to be courageous in the face of severe and unrelating pain, so be it, says traditional morality. For the new advocates of happiness, however, this is all-but unintelligible.
According to Delistraty, however, “if we continue to allow ourselves to be manipulated into pining after peak experiences, then we leave ourselves open … to loneliness, poor judgment and, ironically, an abiding sadness,” citing plenty of research indicating the increased likelihood of depression among those who believe they have a right (and duty) to pursue their happiness. He quotes Aldous Huxley: “the right to the pursuit of happiness … is nothing else than the right to disillusionment phrased in another way.”
Even more, the right to the pursuit of happiness will eventually be understood to be nothing else than the right to abortion, or the right to euthanasia. Eventually, perhaps to a perverse duty to abortion, or euthanasia, or anti-natalism.
We are a people formed to believe in life, liberty, and the pursuit of happiness; increasingly, however, our misunderstanding of happiness is coming at the expense of both life and liberty. Certainly, the new vision of happiness is corrupting our ability to judge sanely and soberly in the domain of bioethics, and we’ll need a better vision of happiness if we wish to protect the most vulnerable and weak in our midst.