Why does A Raisin in the Sun remain relevant today?

Besides the racial elements which sadly still exist today, you might consider Greed. Walter is greedy. He is greedy for what he feels he is entitled to, greedy for success, greedy for something better than what he currently has. This greed blinds him to the needs of his mother and results in him losing a large amount of her money because he falls victim to the kind of person who promises maximum return for minimum effort. The theme of greed deals primarily with Walter and how his greed actually harms his family and himself financially.