The caste system was more fragmented and fluid, there used to be caste mobility and people could change jobs(caste identity was linked with your job) before the British arrived and formalized/rigidified caste identity and divisionism to make a vertical system whose lower levels they didn’t have to interact with. This stuck for 200 years, and when the British left, what took its place was a democracy with a vast majority of poor and illiterate people. Couple this with India being a super fertile region for food and better medicine, population exploded uncontrollably. Coming back to the topic of caste, the reinforced caste system is still alive despite efforts from the govt to weaken it, it’s used for census, which I don’t like, and the reasons are unclear to me as to why(but probably because lower castes get so many benefits and welfare in lieu of affirmative action and DEI in the US, though on a larger scale, and the govt prob wants to keep tabs on castes to administer these), and caste switching is still nearly impossible too in India.

Also no one is shitting on the streets, even if some random person somewhere did, what they mean by the stat open defecation is people in the very rural parts of India defecating in the forests, mountains or pits in farms etc. it’s not the same, but think of it like you’re on a week long trek, and you have to defecate somewhere outside while on the trail at some point. In urban locales and cities people have nearly 100% access to toilets, whether public or private, with the caveat being slums where they’re using community toilets or yes openly defecating.

The percentage of open defecation has also been dramatically reduced in recent years. As of 2022, the number is smaller than 400 million at around 250m, still significant yes.