There is much altruism in humans. Everyone wants to be good. It is only errors in judgment that make people work and fight against each other. Even bad people and criminals honestly believe that they are good. There are many people who are good, want good and do good. Even in our society full of absurd, there are many ways to be helpful to others. Altruistic people often serve to others in obvious ways: they become teachers, nurses, social workers and such. Many artists serve to people through their art. Musicians make people happier with their music. YouTube video creators entertain and teach people via their videos. Some altruistic people help others by focusing maybe on one of few people who are their friends and family. Some altruistic people help animals. Some become monks and serve others by praying. Lightworkers don't become monks, but our work is raising global vibration via individual and collective meditation.
In our life and our design there is much of duality. Everyone contains some of positivity and some of negativity. The art of altruistic life is to filter out negativity in non-destructive ways and positivity in most creative ways. This discrimination allows us to do good and avoid doing damage to others.
Very altruistic are grandparents in their help of bringing up their grandchildren. Their love is more pure and their giving is cleanest. Children who are receiving love of grandparents are the happiest.
Another form of altruism is directed to higher realms. People devote themselves to serving higher purposes. They seek spiritual guidance from higher spheres and do what they believe is most spiritual and most helpful for the god.
Check out "Forest Gump" for illustration of altruism.