I would say these two men did a great deal of harm to human beings in the 20th century. I believe neither of them are generally regarded with that much respect nowadays in the profession they more or less established but, nonetheless, many of their ideas have become absorbed into the general consciousness and continue to do their nefarious work.
If the sexual revolution of the 1960s can be laid at the door of any one man, it would be Freud. Although still not recognised as the destructive force it can be, because we are such materialists, we will one day be forced to recognise that if the sexual instinct is not ruled by a religious understanding then human beings will no longer be able to look up to the sky to see what lies beyond it, and civilisation will start unravelling. We will return to the mud. Freud gave spurious authority to that mud by presenting it as foundational to the reality of what we are. But we were formed of the dust of the earth and the breath of God.
The idea of an atheist pronouncing on the mysteries of the human mind is so absurd you would have thought that Freud's pretensions to knowledge on the subject would be seen as incoherent, but they had enough plausibility to convince a generation softened up by the retreat of religion in the face of materialistic science that he was onto something. It's the old story of a half-truth being worse than a lie. Perhaps the part of the mind he defined as the unconscious had been neglected by earlier generations but to give it such a prominent role in human psychology, and to build a theory of repression on top of it, only serves to encourage and release instincts which are meant to be superseded by first rational and then spiritual impulses. It is not a question of denying the past or the lower or the more primitive but of seeing it in the light of the higher. If it is the higher that is denied then the lower assumes much more importance than it should have. Freud did deny the higher and that fact undermines his whole system.
Jung supposedly reacted to that and tried to re-establish a spiritual sensibility. But did he really? Not in my view. What he did was reduce the spiritual to the psychological which means see the transcendent in the light of the immanent. He reduced God to Man. He might have corrected Freud's reductionism but he established his own which is almost more harmful in the sense that the corruption of the best is the worst. Jung employed pseudo-spiritual terminology and hijacked certain ancient spiritual techniques to bring the divine down to the level of the human mind where it becomes enclosed in our own limitations instead of breaking down those limitations and enabling us to rise above them which it can only do when it remains on its own plane. God is not the image of the Self. He is God.
Jung's big mistake opened the door to many spiritual forms in the late 20th century which sought to steal spirituality from God. They thought they could be more than religion but ended up being less. Both Freud and Jung were false prophets. Their influence was huge but it was only possible in a world that had lost touch with spiritual truth and needed a substitute to compensate for that. They are examples of materialism and the false spirituality that arises as a result of materialism, and although they are no longer regarded with the reverence of earlier decades the damage they did with their ideas has entered the mainstream and carries on undermining the truth.