It seems to me that the author is essentially trying to show how difficult it is for many people to survive in India, especially in the big Indian cities. The astrologer in this story actually has a good day, in spite of the dangerous foe he encounters. He brings home more money than usual--but more money than usual is not very much. His wife is delighted.
"Twelve and a half annas," she said, counting. She was overjoyed. "I can buy some jaggery and coconut tomorrow. The child has been asking for sweets for so many days now. I will prepare some nice stuff for her."
The astrologer started work around noon and hasn't gotten home until nearly midnight. With all his effort he has only managed to acquire enough small coins for food plus a little extra treat for their daughter. What happens when he has a bad day? They have torrential rains in India. There must be days when nobody goes to the park. The astrologer may go there anyway. He always sits under a tamarind tree, a big tree with thick foliation that would protect him from a downpour. He might be able to pick up a few coins and buy enough rice to keep his little family from starving.
In addition to learning about the plight of so many Indian people, an American reader might learn a better appreciation of our relatively luxurious standard of living. Yet we have to admire these people for their fortitude. Most of them have lived like this from day to day for thousands of years. We share R. K. Narayan's sympathy for his people.