The fundamental problem with India is that their higher ups think Western powers will back them up unconditionally. They thought so during Doklam and they still think so now despite evidence to the contrary.
The problem with India is that it's run by Brahmins and Vaishya, not Kshatriya and Shudras. If it were run by a substantial Kshatriya-Shudra alliance, they'd be on the same wavelength as China; the Kshatriyas are the traditional political rulers of India alongside their military castes, and the Shudra caste is their traditional working class. For that, Kshatriya-Shudras, read Confucian Communist in a Chinese mode. The Brahmins are too abstract and theoretical, and Vaishya tend to economic dominance. A Kshatriya-Shudra alliance, in contrast, would be left and progressive based on its constituents (military elites tend to be less conservative than civilian elites because being too conservative gets you killed on the battlefield, Shudras are a potential hotbed of class struggle and worker consciousness).
The big drag on India is the traditional social structure, i.e, the caste system results in massive oppression and human capital wastage. You have Brahmins who pay lip service to anti-Brahmanism (the ideology against the caste system), but in practice they're its beneficiaries and don't want to put in too much effort to bring it down.
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The idea that India would have 4:3 the strength of China is based on a best-case scenario, i.e, it assumes both India and China can successfully modernize and develop. With the caste system in (partial) place, India is not going to be able to successfully modernize and develop unless they do something about it. But let's say they fix it. The 4:3 strength is what the Indians are counting on, but the 4:3 strength isn't sufficient for India to take aggressive action against China vis-a-vis the Arthashastra. So the Indian foreign policy vis-a-vis China is just plain stupid.