Theory (I live half a world away though): totalitarianism. China has a very strong and top-down government, where if the leadership decides for example that streets should be clean, millions of government officials make it happen. I don't know if that is just good organization or if it's backed by e.g. legal repercussions if it's not done right though.
But of course it's got major downsides, as the Chinese government is also pushing hard to remove distinct cultural identities from the various regions of China. India is still much richer in terms of cultures than that, the government can't just come in and start erasing that.
But of course it's got major downsides, as the Chinese government is also pushing hard to remove distinct cultural identities from the various regions of China. India is still much richer in terms of cultures than that, the government can't just come in and start erasing that.