Ancient Greek plays - just entertainment?
The plays performed at the Threatre of Dionysus were not just for entertainment.
For a start, the playwrights competed for a prize. Then, you have to understand the ancient Greek attitude to life. They didn't separate their lives into compartments, as many do in our modern cultures. Their festivals were for enjoyment, worship, business, serious discussion, and much more.
Some of the plays performed were extremely rude (appealing to a male audience), while others tried to make comments or ask questions about serious issues of the day, or attitudes to the gods.
The meaning of our word 'tragedy' comes from the more serious Greek plays. These often concluded that mortals are at the mercy of forces (the gods, destiny, fate) far outside their control or influence.