Yes the country is plainly less rich than Japan and the first world, and it shows in big cities. Even comparing big cities in China to India there is a big gap.
But here is what you are missing: as total wealth in India is growing there are indeed some places (which the casual tourist driving around will not see) centered in Mumbai, Bangalore, Delhi that are super rich. One way to spy on it is visit one of the "five star" hotels like JW Marriots etc -- they are numerous, massive, and full of quite rich people with loads of servants and fancy places to live.
By the way, you can find loads of disgustingly miserable poor places in the rich USA too. Maybe they all have sewers and electricity but that's about all that separates parts of the rural US (deep south) or bad urban poverty (right nearby me in NYC) and some villages in India.