By mere humanitarism or altruism, people do not actually become free from unhappiness.

According to Śrīla Bhaktisiddhānta Sarasvatī, in this world there are different varieties of mercy. But ordinary mercy cannot bring about the cessation of all unhappiness. In other words, there are many humanitarians, altruists and social reformers who certainly work for the betterment of humanity. Such persons are universally considered merciful. But in spite of their mercy, humanity continues to suffer in the grip of birth, old age, disease and death. I may distribute free food to the needy, but even after eating my merciful gift, the recipient will again become hungry, or he will suffer in some other way. In other words, by mere humanitarianism or altruism, people do not actually become free from unhappiness. Their unhappiness is merely postponed or altered.

Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Eleventh Canto, Chapter 02 – Text 30.