Indians are stupid. Period. They believe every stupid survey that any stupid company does in the world, especially, by a white country. They are convinced that everything that western media writes about India is true.
Which material comfort made people happy? Which bridge or building made one happy? If at all, the high-rise buildings and concrete jungles make one depressed.
What gives people happiness is the love that they exchange with each other. In India, relationships are given so much importance. Relationships give people security and happiness. So, I would even claim that India is one of the happiest countries in the world. I find people in India to be happier than people in US (these are the only two countries I have seen), even though they may have nothing.
Unfortunately, we are becoming more and more materialistic, so I would not be surprised that we might indeed become one of the most depressed countries in the world in the near future. But, as of today, I do not believe this.